Review
DOI: 10.1002/ijch.201900179

Buchwald-Type Ligands on Gold(I) Catalysis
Giuseppe Zuccarello+,[a] Margherita Zanini+,[a] and Antonio M. Echavarren*[a]

Abstract: Dialkyl biarylphosphine ligands, presented in the
context of Pd-catalyzed cross-coupling reactions, have been
extensively applied in gold(I) catalysis giving rise to numerous transformations and reaction pathways otherwise inaccessible under the action of other gold(I) catalysts. This
review emphasizes how this privileged ligand class, as well

as recent modifications on the biarylphosphine motive, have
triggered the discovery of new reactivities in our research
program. Finally, the introduction of chiral information on
the ligand scaffold provides new solutions to challenging
gold(I)-catalyzed enantioselective transformations.

Keywords: Gold(I) catalysis · Biarylphosphines · cyclizations · asymmetric catalysis · alkynes

1. Introduction
For many years gold was considered to be catalytically
inactive and therefore overviewed from the chemical community until the first report on gold(I)-catalyzed transformations
by Ito and Hayashi[1] marked a starting point in the field of
homogenous gold(I) catalysis. Later, the preparation of ketones
by addition of alcohols or water to alkynes reported by Teles[2]
and Tanaka[3] respectively, as well as the gold(III)-catalyzed
phenol synthesis by Hashmi[4] unrevealed the potential of gold
catalysts as carbophilic π-acids in synthetic organic chemistry.
The groups of Toste,[5] Fürstner[6] and our own group[7]
identified cationic phosphine gold(I) catalysts [R3PAuX] (X =
labile anionic ligand) formed in situ from [R3PAuCl] by
chloride abstraction with AgX or by protolysis of [R3PAuCH3],
to be the most active and selective in the cyclization of 1,nenynes and other CÀ C[8–11] and carbon-heteroatom[12–14] bondforming reactions. In the first decade of the current century,
homogeneous gold(I) catalysis has experienced a “gold rush”
during which numerous transformations were developed for
the assembly of complex molecular settings,[15–20] that were
also applied in the context of natural product total
synthesis.[21,22] Gold(I) carbenes were invoked as key intermediates in many of these transformations whereby their
reactivity is strongly determined by the ancillary ligand.[23]
According to the binding model described by Toste and
Goddard,[24] gold(I) binds linearly via backdonation of its
electrons in the filled 5d orbitals into the empty π orbitals of
the ligand and the carbene. Hence, more σ-donating ligands
such as N-heterocyclic carbenes (NHC) result in more
carbene-like intermediates with according reactivity whereas a
carbocation-like behavior is obtained with π-acidic phosphite
ligands (Scheme 1).[23]
Between these two extremes, bulky dialkyl biarylphosphine ligands introduced by Buchwald in 1998 for Pdcatalyzed coupling reactions,[25] provide electronically and
sterically an intermediate alternative. Due to their stability
with respect to oxidation[26] and synthetic accessibility,[27] this
class of ligands has been employed in numerous Pd-catalyzed

Isr. J. Chem. 2020, 60, 1 – 14

Scheme 1. Dialkyl biarylphosphine-supported gold(I) complexes.

CÀ C[28,29] and CÀ X (X=N, O, F)[30–33] bond-forming reactions
as well as in combination with other transition metals such as
Ag,[34] Rh,[35,36] Ru[37] and Cu.[38]
Our group introduced the use of dialkyl biarylphosphine
ligands in the context of gold(I) catalysis[39] resulting in a new
family of highly electrophilic gold(I) complexes A–D which
were found to catalyze diverse transformations upon chloride
[a] G. Zuccarello,+ M. Zanini,+ A. M. Echavarren
Institute of Chemical Research of Catalonia (ICIQ), Barcelona
Institute of Science and Technology, Av. Països Catalans 16, 43007
Tarragona (Spain)
and
Departament de Química Analítica i Química Orgànica, Universitat
Rovira i Virgili C/ Marcel·lí Domingo s/n, 43007 Tarragona (Spain)
E-mail: aechavarren@iciq.es
[+] These authors contributed equally to this work.
© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co.
KGaA.
This is an open access article under the terms of the Creative
Commons Attribution Non-Commercial License, which permits use,
distribution and reproduction in any medium, provided the original
work is properly cited and is not used for commercial purposes.

© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

1

These are not the final page numbers! ��

Review
abstraction. Importantly, cationic complexes E–G are easily
accessed from their gold chloride precursors by treatment with
AgSbF6 and are bench-stable white solids that can be directly
used in catalysis without pre-activation.
In this account we review the impact of biarylphosphine
ligands on our program on gold(I) catalysis, spanning from
their first appearance in the field to several different transformations including cyclizations of 1,n-enynes, cascade
reactions of 1,6-dienynes and the generation of gold(I)
carbenes by decarbenation of 7-substituted cycloheptatrienes.
Hereby, the differences in reactivity and selectivity arising
from the use of complexes A–G and other gold(I) catalysts
will be compared and highlighted. Additionally, unprecedent
reactivities that have been disclosed upon modification of the
biaryl framework, including efforts from the Zhang group on
the design of bifunctional biarylphosphine ligands featuring a
remote basic site, are summarized. Finally, the particular
geometry and rigidity of the biaryl scaffold has provided the
optimal platform for the design of chiral modifications
allowing for their implementation in asymmetric gold(I)
catalysis.

Giuseppe Zuccarello was born in Basel (Switzerland) in 1990. He received his B.Sc. degree
in Chemistry from the University of Basel and
completed his Master studies in Chemistry at
the Swiss Federal Institute of Technology in
Zürich (ETHZ). After a one-year internship at
Syngenta AG in Stein (Switzerland) he joined
the research group of Prof. Antonio M. Echavarren at the Institute of Chemical Research of
Catalonia (ICIQ) in Tarragona (Spain) where he
is currently pursuing his doctoral studies. His
research interests include the development of
new chiral gold(I) complexes and their application in catalysis.
Margherita Zanini was born in Rome (Italy) in
1992. She performed both her B.Sc. and M.Sc.
in Chemistry in the University of Bologna.
Afterwards, she joined the group of Prof.
Antonio M. Echavarren at the Institute of
Chemical Research of Catalonia (ICIQ). She is
currently performing her fourth year of PhD
studies in the Echavarren group. Her main
research interest is the development of new
transition metal-catalyzed transformations,
mainly focusing on gold(I) homogeneous catalysis.

Isr. J. Chem. 2020, 60, 1 – 14

2. Reactivity and Structure of Buchwald-type
ligands-supported Gold(I) Complexes
2.1 Access to new Reactions
2.1.1 Formal [4 + 2] Cycloadditions of 1,n-enynes
In the presence of a cationic gold(I) complex, 1,n-enynes can
follow diverse reaction pathways depending on their substitution pattern on the alkene and the alkyne.[5–7,40–42] Even though
most of these transformations are catalyzed by [PPh3AuCl]
upon chloride abstraction, enynes containing internal alkynes,
particularly arylenynes, display a reduced reactivity.[43] Hence,
in 2005 our group introduced dialkyl biaryl phosphine
supported gold(I) complexes A-D in the context of the formal
[4 + 2] cycloaddition of 1,6-arylenynes 1 forming 2,3,9,9atetrahydro-1H-cyclopenta[b]naphthalenes 5 (Scheme 2).[39]
The bulkier Buchwald-type ligands provided an enhanced
catalytic activity compared to NHC-gold(I) complexes and
afforded the target compounds in shorter reaction times and
higher chemical yield. Experimental and theoretical studies
support the reaction mechanism to proceed via 5-exo-dig
formation of anti-cyclopropyl gold(I)-carbene 2 which is then

Prof. Dr Antonio M. Echavarren was born in
Bilbao (Spain). He received his PhD at the
Universidad Autónoma de Madrid (UAM,
1982) in the group of Prof. Francisco Farina
After a postdoctoral stay in Boston College with
Prof. T. Ross Kelly, he joined the UAM as an
Assistant Professor. Following a two years
period as a NATO-fellow with Prof. John K.
Stille in Fort Collins (Colorado State University), he joined the Institute of Organic
Chemistry of the CSIC in Madrid. In 1992 he
returned to the UAM as a Professor of Organic
Chemistry and in 2004 he moved to Tarragona
as a Group Leader at the Institute of Chemical
Research of Catalonia (ICIQ). In 2013 he got an
ERC Adv. Grant to develop gold catalysis and in
2019 a second ERC Adv. Grant to develop new
catalysts for the biomimetic cyclization of
unsaturated substrates. Prof. Echavarren is a
member of the International Advisory Board of
Organic & Biomolecular Chemistry, Chemical
Society Reviews, and Advanced Synthesis and
Catalysis, member of the Editorial Board of
Chemistry European Journal, and Associate
Editor of Chemical Communications. He is a
Fellow of the Royal Society of Chemistry. He
received the 2004 Janssen-Cylag Award in
Organic Chemistry and the 2010 Medal of the
Royal Spanish Chemical Society and an Arthur
C. Cope Scholar Award from the ACS. He is the
President of the Spanish Royal Society of
Chemistry (RSEQ).

© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

www.ijc.wiley-vch.de

2

These are not the final page numbers! ��

Review
outcompeted catalysts supported by NHC- and phosphite
ligands resulting in the cleanest reactions.
Starting from readily available iodoarenes a broad scope of
hydroacenes were accessed spanning from functionalized
dihydrotetracenes 8 a and partially saturated heteroacenes 8 b
to extended dihydrotetracenes 8 c and polyhydroacenes 8 d,
formed via multiple gold(I)-catalyzed cyclization and aromatization reaction. Shortly after, the entire series of higher acenes
from heptacene to undecacene has been successfully synthesized stepwise on a Au(111) surface through dehydrogenation
from their corresponding partially saturated precursors.[51,52]
Scheme 2. Formal [4 + 2] cycloaddition of 1,6-arylenynes 1.

2.1.2 Comparison of Catalyst-dependend Reactivities in
Cyclizations of 1,n-enynes and Cascade Reactions
opened by a Friedel-Crafts-type reaction to form Wheland
intermediate 3. Sequential proton loss and final protodeauration from 4 affords 5.[44]
The formal [4 + 2] cycloaddition of 1,7-enyne 7 where the
alkene is replaced by an enol ether leads to the formation of
dihydrotetracenes 8 (Scheme 3). This reaction proceeds similarly via 6-endo-dig cyclization pathway and the concomitant
aromatization by loss of one molecule of methanol.[45]
Dihydroacenes are hydrogen-masked, precursors[46] for the
in situ formation of acenes,[47] a class of linear polycyclic
hydrocarbons that find their application in organic
electronics[48,49] and as organic semiconducting materials.[50]
However, the isolation of oligoacenes becomes more difficult
with increasing length (n > 6) because of their air- and photoinstability and reduced solubility. Thus, we disclosed a
sequential Sonogashira coupling/gold(I)-catalyzed cyclization
sequence for the synthesis of higher hydroacenes and
polyhydroacenes. Again, cationic JohnPhos-gold(I) catalyst E

Scheme 3. Access to hydroacenes via sequential Sonogashira coupling/gold(I)-catalyzed 1,7-enyne cyclization.

Isr. J. Chem. 2020, 60, 1 – 14

Buchwald ligand-supported gold(I) catalysts not only stand out
for being robust and highly reactive but can display different
chemo- and regioselectivities compared to other catalysts
giving access to compounds otherwise difficult to synthesize.
1,6-Enyne 9 undergoes 5-exo-dig cyclization to form cyclopropyl gold(I)-carbene intermediate 10 which was found to be
a bifunctional electrophile (Scheme 4).[53] Depending on the
catalyst of choice, in the presence of an external nucleophile
such as indole or electron-rich arenes intermediate 10 reacts
either at the carbene carbon a or at the cyclopropyl carbon b.
The use of cationic catalyst E afforded a 4 : 1 mixture of 11
and 12 arising from the preferential reaction at carbon a,
whereas different selectivity was found using IMesAuCl and
AgSbF6 slightly in favor of 12 (1:0.8).
A comparable switch in selectivity was observed in the
gold-catalyzed hydroarylation of alkynes[54–56] reported by our
group (Scheme 5).[11,57] The reaction outcome of the intramolecular hydroarylation of alkynyl indoles 13 was found to
be strongly dependent on the catalyst employed. In general,
the use of AuCl3 or AuCl salts lead to the selective formation
of indoloazocine 14, whereas cationic complex E afforded
exclusively azepino[4,5-b]indole 15. The isolation of a spiro
derivative indicates that a stepwise reaction mechanism takes
place in this process. First, intermediates 15 and 16 are
respectively formed via a 7-endo-dig and 6-exo-dig aromatic
electrophilic substitution at the more nucleophilic C-3 carbon.

Scheme 4. Bifunctional electrophilic reactivity of intermediate 10.

© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

www.ijc.wiley-vch.de

3

These are not the final page numbers! ��

Review

Scheme 6. Gold(I) catalyzed reactions of 1,6-enyne functionalized
with propargyl acetate.
Scheme 5. Gold-catalyzed hydroarylation of alkynyl-indoles and synthetic application in total synthesis of Kopsia indole alkaloids.

Sequentially, a 1,2-alkyl shift[58,59] leads to the corresponding
products.[60] Interestingly, catalyst E proved superior to
[PPh3AuCl]/AgSbF6 giving 14 and 15 as a 1 : 4 mixture.
Recently, our group has demonstrated the potential of the
gold-catalyzed intramolecular hydroarylation of indoles to
construct the pyrroloazocine indole core in 17[61] which was
later applied in the total syntheses of Kopsia alkaloids[62] (À )lundurines A-C[63] and seven members of the lapidilectine/
grandilodine family.[64]
Analogously, gold(I) complexes supported by Buchwaldtype phosphines are able to modulate the reactivity of 1,6enyne bearing propargylic alcohols, ethers or silyl ethers. In
fact, enynes with a propargyl acetate such as 18 react in
presence of gold(I) catalyst E via cyclopropyl gold(I) carbene
19 to form an intermediate that can be represented as an α,βunsaturated gold(I)-carbene (20) or a gold(I) stabilized allyl
cation (21) via 1,5-migration of the OAc group
(Scheme 6).[65,66] Intermediates 20/21 can react with 1,3diketones as nucleophiles to give products of α-alkylation,[66]
as well as with electron rich heterocycles such as indole[65] or
furans.[67]
The carbene nature of intermediate 20 is revealed in the
reaction with electron rich alkenes to form the corresponding
cyclopropane.[65,66] In contrast, in presence of AuCl3 enyne 18
undergoes initial 1,2-acyl migration to form α,β-unsaturated
gold(I)-carbene 25 followed by cyclopropanation of the
appended double bond.[68]
We applied these findings in the first enantioselective total
synthesis of (+)-schisanwilsonene A starting from enantioenriched enyne 27 (Scheme 7).[69] The partial racemization
during the key gold(I)-catalyzed 1,5-acyl migration is ascribed
to the competing 1,2-acyl migration. However, in this case this
process is ca. 20 time slower than the desired reaction.
In the effort to involve gold(I) in cascade reaction for the
rapid construction of complex carbon skeletons, we discovered

Isr. J. Chem. 2020, 60, 1 – 14

Scheme 7. Enantioselective total synthesis of (+)-schisanwilsonene
A.

the formal [2 + 2 + 2] cycloaddition of 1,6-enyne bearing a
keto group[70] (Scheme 8). The reaction begins with the
formation of cyclopropyl gold(I) carbene 32. Upon intramolecular attack of the carbonyl, the oxonium cation 33 is
formed. Prins-type cyclization followed by demetalation leads
to the assembly of the oxatricycle 35 from linear precursor 31.
Interestingly, protected cyclopropanols such as 36 can act
as masked activated ketones that are revealed upon a gold(I)

Scheme 8. Gold(I)-catalyzed [2 + 2 + 2] cycloaddition of 1,6-enynes.

© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

www.ijc.wiley-vch.de

4

These are not the final page numbers! ��

Review
catalyzed cyclization/ring expansion cascade (38 and 41,
Scheme 9). Again, the sequence is closed via a Prins-type
reaction to form a tricyclic product featuring an octahydralcyclobutane[a]pentalene skeleton occurring in a number of
protoilludane-related sesquiterpenes. During the optimization
of the reaction, AuCl outperformed other catalysts in the
formation of the anti-diastereomer. However, the syn-diasteroisomer is obtained selectively with E as catalyst. This result
can be rationalized taking into account the different stability of
the intermediates in presence or in absence of the ligand. Once
37 is formed, it evolves rapidly into 38 oxonium cation with
AuCl as catalyst, resulting into a diasteroselective reaction. On
the other hand, catalyst E favors a non-concerted mechanism
for the ring expansion through 41 and 42, in which the
stereochemical information is lost.

Scheme 9. Different diasteroselectivtiy in the gold(I)-catalyzed [2 + 2
+ 2] cycloadditon of 1,6-enyne functionalized with cyclopropanols.

Scheme 10. Totals synthesis of natural sesquiterpene repraesentin F.

Isr. J. Chem. 2020, 60, 1 – 14

It is important to note that when the steric hindrance
around the carbocation increases by addition of a methyl as in
the case of 45 (Scheme 10), the equilibration between the two
cations is blocked with a gold complex bearing a bulky
phosphine and the ring expansion occurs stereospecifically.
We took advantage of this reactivity in the total synthesis of
repraesentin F (48),[71] in which the core skeleton is assembled
in a single step via a diasteroselective gold(I)-catalyzed enyne
cyclization/ring expansion/Prins cyclization cascade. The
increase in the steric hindrance on the second aromatic ring of
the ligand of catalyst H results in an improved diastereomeric
ratio in the formation of 47 a and 47 b.

2.1.3 Formation of Gold Carbenes via
Retro-Cyclopropanation and Retro-Buchner Reaction
Interested in broadening the scope of the tandem 1,n-enyne
cyclization/(1,n-1)-migration,[65] our group studied the reactivity of arene-tethered 1,6-enyne 49 containing a propargyl ether
(Scheme 11).[72] To our surprise, in presence of catalyst E we
observed the formation of 3-aryl-1-methoxynaphtalenes 50
accompanied by biscyclopropane 51 as a minor compound.
We hypothesized that, after formation of cylopropyl gold
(I)-carbene 52 by 6-endo-dig cyclization, followed by a [1,2]hydrogen shift[73] giving alkenylgold(I) intermediate 54 via 53
a retro-cyclopropanation was taken place to form naphthalenes
50 and gold(I)-carbene 55, which reacts with a molecule of 54
to afford 51. Beside disclosing a new synthesis of 1,3substituted naphtalenes which are otherwise not readily
available, we recognized the synthetic potential to generate
gold(I)-carbenes from benzofused norcaradiene derivatives 54
by retro-cyclopropanation.[74]
However, the preparation of derivatives 54 is not
straightforward. Hence, our group implemented the use of 7substituted-1,3,5-cycloheptatrienes 56 for the generation of
gold(I)-carbenes 58 (Scheme 12).[75] Cycloheptatrienes 56 are
in equilibrium with their norcaradiene tautomers 57,[76,77]
which react with electrophilic gold(I) complexes by a stepwise
retro-cyclopropanation[78] to generate gold(I)-carbene 58 together with one molecule of benzene resulting in an overall

Scheme 11. Synthesis of naphthalenes via retro-cyclopropanation.

© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

www.ijc.wiley-vch.de

5

These are not the final page numbers! ��

Review

Scheme 12. Diverse reactivity of gold(I)-carbenes generated by retroBuchner reaction.

retro-Buchner process. Gold(I)-carbene 58 can then be trapped
inter- and intramolecularly with different alkenes giving rise to
a number of synthetically useful transformations.[75] The use of
cycloheptatrienes as carbene precursors represents a much
safer alternative compared to the more conventional generation
of metal carbenes from diazo compounds due to their thermal
stability. Furthermore, the starting materials are easily accessible in multigram scale by addition of the corresponding
organolithium or Grignard reagent to commercially available
tropylium
tetrafluoroborate
or
via
Julia-Kocienski
olefination.[79,80]
The reaction of the gold(I) carbenes generated by the retroBuchner reaction with alkenes leads to a broad scope of di-,
tri-aryl- and vinyl cyclopropanes 59 and 60 (Scheme 12)[79,81,82]
Highly substituted cyclopentenes 65 are formed through a
formal (4 + 1) cycloaddition by reaction of methylenecyclopropanes 61 or cyclobutenes 62 as 1,3-dienes
equivalents.[83] The overall transformation is particularly
intriguing since the gold(I)-catalyst is involved in three
different catalytic steps. Beside generating gold(I)-carbene 58,
methylenecyclopropane 61 is isomerized to cyclobutene 62,
which is cyclopropanated giving bicyclo[2.1.0]pentanes 63.
Cleavage of the internal CÀ C bond is also promoted by gold(I)
to form 64, which undergoes a [1,2]-hydrogen shift to afford
65. Allenes also react with aryl- and styryl-gold(I)-carbenes 58
giving indenes 66 and cyclopentadienes 67, respectively, by a
formal (3 + 2) cycloaddition.[84] The potential of these trans-

Isr. J. Chem. 2020, 60, 1 – 14

formations was demonstrated in the total synthesis of (�)laurokamurene B[85,86] and in the assembly of the tetracyclic
carbon skeleton of the cycloaurenones[87] and dysiherbols[88]
family of natural products.
Similarly, 7-aryl-cycloheptatreienes of type 68 react intramolecularly through generation of gold(I)-carbene 69 to give
indene and fluorene derivatives 70 following a Friedel-Craftstype mechanism.[82] Finally, gold(I)-carbenes generated by
retro- Buchner reaction also undergo C(sp3)À H insertion to
give substituted indanes 73 and 3-aryl-1,2-dihydronaphtalenes
74 from 71 and 72, respectively. In these transformations,
cationic NHCgold(I)-complex were found to be superior
catalysts.[89]
In spite of the numerous transformations streamlined by
the gold(I)-catalyzed retro-Buchner reaction, their set-ups
require relatively elevated temperatures (75–120 °C) diminishing stereo control and functional group tolerance. Recently,
our group addressed this limitation designing a second
generation of 7-styryl-1,3,5-trimethyl-cycloheptatrienes 75
(Scheme 13).[80] The electron-donating substituents stabilize
Wheland-type intermediate 77 formed upon cleavage of the
first CÀ C bond in norcaradiene 76, which is the ratedetermining step of the retro-Buchner process.[79,81] After
releasing one molecule of mesitylene, gold(I)-carbene 78 is
generated. In comparison with the first generation of
cycloheptatrienes,[79] compounds 79 react in presence of
catalytic amounts of catalyst E at 25 °C with a broad range of
alkenes giving vinyl cyclopropanes 81 with improved cis-

Scheme 13. Second generation 7-styryl-1,3,5-trimethyl-cycloheptatrienes. Isolated yield and cis/trans ratio of diastereosiomers in
parentheses. In grey: yield and diastereoselectivity obtained with first
gen. of cycloheptatriene.

© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

www.ijc.wiley-vch.de

6

These are not the final page numbers! ��

Review
diastereoselectivity. Importantly, this new generation of cycloheptatrienes underwent retro-Buchner reaction also in presence
of zinc-and and rhodium-based catalysts.[90]

2.2 Structural Considerations and Variation of the Biaryl
Scaffold
When coordinated to palladium, bulky biphosphine ligands
display a Pd-arene interaction considered to be key for the
successful reactivity in cross-coupling reactions.91–93] Since
these ligands also demonstrated to be privileged scaffolds in
the context of gold(I) catalysis, it was important to determine
if an analogue metal-arene interaction was actually taking
place and was playing a role in the enhanced reactivity
demonstrated by these complexes.
For cationic complex E, the distance between the second
aromatic ring of the ligand and the gold atom is 3.03 Å,[94]
similar to the one observed in anthracene complex 82 (AuÀ C
distances of 2.958 Å and 3.097 Å) (Scheme 14).[95] These
values are above the limit of significant interaction for Au and
an arene calculated to be of 2.95 Å.
By crystallization of complex E in toluene or p-xylene, the
aromatic solvent displaces acetonitrile as ligand forming
complexes 83 a and 83 b with a η1/η2 coordination of the arene
to gold(I) (Scheme 14).[94] In these cases, the distance between
the aromatic plane and the metal is of 2.20–2.24 Å, which
corresponds to a stronger arene-gold(I) interaction. According
to these data, the M-arene interaction, which is key for
palladium, does not occur in the analogues Au(I) complexes.

Scheme 14. Structure of cationic gold(I) complexes with very weak
and strong arene-metal interactions.

Scheme 15. Cationic gold(I), silver(I) and copper(I) complexes with
tBuXPhos as ligand.

Isr. J. Chem. 2020, 60, 1 – 14

We also studied the structural differences of the isoleptic
family of complexes 84–86 having tBuXPhos as ligand
(Scheme 15).[30] As already observed with JohnPhos supported
complexes, Au(I) displays an almost linear coordination with a
PÀ MÀ N angle of 173.1°, whereas Ag(I) and Cu(I) congeners
are more bendt showing PÀ MÀ N angles of 168.0° and 148.8°,
respectively. As expected, the metal-ligand distance follows
the order Cu < Au < Ag. The interaction with the parallel
aromatic ring in the phosphine ligand is again above the limit
for a significance bonding interaction in the case of gold
(observed MÀ Cispo 3.04 Å). In contrast, Ag(I) and Cu(I)
display a strong interaction with the aromatic ring (the limit
for a meaningful metal-arene interaction for Ag(I) and Cu(I)
are 3.03 Å and 2.83 Å, respectively). It is also important to
remark that computational studies on the natural population of
these complexes indicate the absence of electron transfer from
the arene to the metal, which excludes a covalent character for
this interaction.
Many other studies on the structure and the nature of
cationic gold π-coordinated complexes with alkenes, alkynes,
dienes, allenes, arenes and heteroatom substituted π-ligands
have been performed.[96] What it emerges from those studies is
that the these electron-donating bulky ligands stabilizes neutral
and cationic linear gold π-complexes and can be also
responsible of a certain stabilization of the metal carbene, or
cationic-like intermediate, generated in the catalytic activation
of unsaturated CÀ C bonds.

2.2.1 Electronic Tuning of the Biaryl Scaffold
Despite the success of o-biphenyphosphines as ligands and the
extensive studies performed on the structural features of the
related gold(I) complexes, the variation of the electronic
properties of this ligand motif has been neglected until
recently.
The group of Fernández and Lassaletta[97,98] reported the
synthesis of a series of ligands in which the privileged biaryl
scaffold is incorporated into an imidazole core to give rise to a
new family of chiral NHCÀ Au(I) complexes. Our group also
reported the synthesis, structural analysis and the exploration
of the catalytical activity of a new family of Au(I) complexes
with ligands structurally inspired on JohnPhos, but with
significantly altered electronic characteristics (Scheme 16).[99]
On one side, we synthesized the As-based analogous of
JohnPhos, that displays a stronger π-acceptor character, on the
other, we incorporated the 4-aryindazole scaffold into the
biaryl system of a small library of ligands with high σdonating character (Scheme 16).
The structure of the As-based dialkyl-biphenyl gold(I)
complexes are in line with what already reported for other As
based gold(I) complexes.[100–102] Compared to the phosphorous
analogous, the AuÀ Cl or AuÀ N distance is shorter, in line with
the expected increased electrophilicity of the complexes. In
the attempt of synthesizing the cationic gold(I) π-complexes
with simple alkenes starting from complex 87, we isolated

© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

www.ijc.wiley-vch.de

7

These are not the final page numbers! ��

Review
Table 1. Gold(I) catalyzed addition of indole to 1,6-enyne 9.

Entry

quantitatively complexes 88 and 89, in which the double bonds
of the original alkenes have undergone migration (Scheme 16).
This 1,3-hydrogen migration probably occurs by Brønsted acid
catalysis outside the coordination sphere of the metal and can
be induced also in preformed complexes both with arsine or
phosphine ligand. The alkene is closer to the metal center in
the arsine complexes compared to the phosphine analogues in
agreement with the observed higher electrophilicity of the
arsine complexes. The enhanced steric congestion around the
metal center is also probably responsible for the counterintuitive isomerization of the internal double bond to the
terminal one in 89.
Structurally, the 4-arylindazole family of gold(I) resemble
the structure of gold(I) complexes with a simpler similar
ligand already reported.[103] Notably, complex 90 e, with a very
electron-poor second aromatic ring, showed the CipsoÀ Au
distance to be 0.2–0.3 Å shorter than that found in the rest of
the family. The angle between the two aromatic rings of 90 e is
around 90°, instead of 50–55° in the other complexes. In this
way, the ligand of complex 90 e resembles more the obiarylphosphine skeleton of JohnPhos.
This difference in structure causes also a drastic change in
reactivity in homogeneous gold(I) catalyzed reaction. As an
example, we tested the library of new complexes in the
addition of indole to 1,6-enyne 9 (Table 1). As mentioned
before (see Scheme 4), the outcome of this addition reaction
depends on the nature of the catalyst and can be correlated

Isr. J. Chem. 2020, 60, 1 – 14

Yield [%] (12 : 11 ratio)

1
2
3
4
5
6

Scheme 16. Structure and reactivtiy of dialkyl-biaryl arsine gold(I)
complexes and 4-arylindazole gold(I) complexes.

Catalyst
87 a
90 a/AgSbF6
90 b/AgSbF6
90 c/AgSbF6
90 d/AgSbF6
90 e/AgSbF6

95 (69 : 31)
21 (20 : 80)
42 (25 : 75)
73 (40 : 60)
41 (33 : 67)
61 (75 : 25)

with its electrophilicity.[53] As expected, the arsine gold(I)
complex 87 gave 12 as the major product (Table 1, entry 1)
whereas the indazole gold(I) complexes 90 a–d led preferentially to 11 (Table 1, entries 2–5). However, complex 90 e
differentiates from the rest of its congeners and leads 12 as the
major product (Table 1, entry 6) stressing the similar behavior
of this complex with o-biarylphosphine gold(I) complexes.

2.2.2 Functionalized Biphenyl Scaffolds in Gold(I) Catalysis
The bulky biarylphosphine ligands have attracted interest also
from the geometrical point of view. Functionalization on the
rigid biphenyl scaffold has led to the uncovering of new
reactivities and to improve the selectivity of known transformations. In this context, the group of Zhang has introduced
a family of ligands based on the biarylphosphine framework
allowing for ligand-directed anti-nucleophilic additions to
alkynes.[104] In their design, the second aryl ring is functionalized at the 3’-position with hydrogen-bond acceptor functional
groups such as amines and amides (Scheme 17). In view of the
outer-sphere reaction mechanism in gold(I)-catalyzed transformations, the rigid biphenyl scaffold represents the optimal
platform to place a distal functional group assisting the
nucleophilic attack onto a coordinated alkyne substrate. Thus,
for example, the intermolecular reaction becomes a partially
intramolecular process where the remote amide in ligand L1
pre-orientates the nucleophile acting as a general base in the
first place, and secondly as a general acid catalyst, promoting
a rapid intramolecular protodeauration. This results in an
increased reaction rate and overall reaction efficiency.
In general, additions of carboxylic acids, anilines and water
to alkynes could be performed in high yields and turnover
numbers (TONs) (up to 99,000) with ppm level of catalyst
loadings.[104] Importantly, this class of ligands outcompetes

© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

www.ijc.wiley-vch.de

8

These are not the final page numbers! ��

Review

Scheme 17. Bifunctional biarylphosphine ligands and application in
the addition of carboxylic acids to alkynes.

more conventional ligands employed in these transformations
such as JohnPhos and NHC ligands.
This soft deprotonation strategy has streamlined the synthesis of a library of dialkyl biarylphosphine ligands L2–L5
which bear a remote amine leading to the discovery of new
reactivities in gold(I) catalysis (Scheme 18). Thus, the group
of Zhang reported the isomerization of alkynes 91 to 1,3dienes 93.[105] In this reaction, the propargylic hydrogen is
acidified upon activation of the alkyne by gold(I) and the
strategically positioned weak Brønsted base functions as a
proton shuttle in the isomerization process, which leads to the
formation of allenyl intermediate 92. Similarly, the isomerization of ynamides and allenamides,[106] propargylic esters[107]
and allyl ynoates[108] has been reported.
This class of ligands has enabled the development of
intermolecular processes such as the hydroalkenylation of
propargylic alcohols 94 with alkenyltrifluoroborates 95
(Scheme 18).[109] In this transformation, the hydrogen-bond
between the basic site and the propargylic alcohol increases
the nucleophilicity of the oxygen, which in turn facilitates
reaction with an alkenylboronate forming cyclopropylgold(I)
carbene intermediate 96, and subsequently dienol 97. Finally,
silylated alkynes 98 also undergo an isomerization reaction to
generate an intermediate σ-allenylgold 100 that is stabilized by
a
β-silicon
effect
rather
than
undergoing
fast
protodeauration.[110] This allowed the reaction with electrophiles such as aldehydes 99 via 1,2-addition, followed by
cyclization with concomitant 1,2-silyl migration yielding
silylated dihydrofuranes 101 (Scheme 18).[111]

Isr. J. Chem. 2020, 60, 1 – 14

Scheme 18. Versatility of biaryl phosphine ligands L2–L5 with remote
basic functional groups in gold(I) catalysis.

2.2.3 Buchwald-type Ligands in Enantioselective Gold
(I)-catalysis
In contrast to the broad scope of gold(I)-catalyzed transformations reported over the last 15 years, the enantioselective
counterparts
have
experienced
much
slower
development.[112–114] The associated difficulties are mainly
attributed to the preferred linear dicoordination adopted by
gold(I), which places the ancillary chiral ligand and the
substrate opposite to each other, resulting in poor enantioinduction. In addition, gold(I)-catalyzed addition reactions to
unsaturated functional groups such as alkynes take place by
outer sphere mechanisms, thus enhancing the degree of
difficulty in developing enantioselective processes. Despite
significant
progress
using
axially
chiral
digold
complexes,[43,115,116] phosphoramidite ligands,[117] the combination of non-chiral gold(I) complexes with chiral counterions[118]
and other emerging strategies,[119–124] the asymmetric activation
of alkynes which are not prochiral still presents an important
challenge.

© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

www.ijc.wiley-vch.de

9

These are not the final page numbers! ��

Review
In line with their pioneering studies, the group of Zhang
reported bifunctional ligand L6 which enables the synthesis of
chiral 2,5-dihydrofuranes 103 via enantioselective isomerization of propargylic alcohol 102 to axially chiral allenes
followed by stereospecific cyclization (Scheme 19).[121] Additionally, the same group reported a ligand-accelerated enantioselective cyclization of allenols.[122] Key to this transformation
was the use of axially chiral ligand L7 with a remote amide
group whereby hydrogen-bonding between ligand and substrate asymmetrically pre-orientates allenol 104 for nucleophilic attack giving vinyl tetrahydrofuranes 105.
In view of the general applicability of Buchwald ligands in
gold(I)-catalysis, our group introduced a new family of chiral
mononuclear gold(I) complexes 106–112 supported by modified JohnPhos-type ligands containing a remote C2-symmetric

Scheme 19. Application chiral biarylphosphine ligands with remote
functional group.

2,5-diarylpyrrolidines (Scheme 20).[125] The design of this class
of ligands was streamlined by the challenge of placing the
chiral information around the reactive center (substrate). To
overcome this difficulty, we recognized that the geometry of
the bulky dialkyl biphenyl-phosphine ligands was suitable to
address the limitations presented by the particular coordination
mode of gold(I). In our design, the rigid biaryl scaffold
connects the chiral element and the coordinating phosphine
encapsulating the gold(I) nucleus in a chiral pocket. The bulky
dialkyl phosphines are crucial to prevent rotation around the
Caryl-P bond and force the PÀ AuÀ Cl axis to be parallel to the
biphenyl scaffold and point towards the chiral information
We applied these chiral complexes in three different
cyclizations of 1,6-enynes 113, 115 and 117 giving products of
formal [4 + 2] cyclization 114, azabicyclo[4.1.0]hept-4-enes
116 and 1,2-dihydronaphtalenes 118 in high yields and
enantioselectivities (Scheme 21).[125] Additionally, we demonstrated the synthetic utility of products 118 for the first
asymmetric total synthesis of three members of the carexane
family of natural products.
The simple design of the mononuclear complexes facilitated the systematic investigation of their mode of action.[125]
Remarkably, despite the structural similarity of 1,6-enynes 113
and 117 opposite enantioselectivites were obtained arising
respectively from the reaction of the Si or Re faces of the
alkene, which indicates that a totally distinct folding of the
unsaturated substrates takes place inside the chiral pocket.
Theoretical and experimental evidence showed that attractive
non-covalent interactions between the aromatic moieties of the
substrates and the aromatic substituent of the distal pyrrolidine
are responsible for substrate recognition favoring one specific
binding orientation (A or B) and in turn the reaction of one
face of the alkene over the other (Scheme 22). Additional π-π-

Scheme 20. Family of chiral mononunclear gold(I) catalysts 106–112.

Isr. J. Chem. 2020, 60, 1 – 14

© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

www.ijc.wiley-vch.de

10

These are not the final page numbers! ��

Review
3. Summary
Bulky dialkyl biarylphosphines, developed by Buchwald as
ligands for Pd-catalyzed reactions, are also privileged ligands
in homogeneous gold(I) catalysis. However, there are some
important differences in the metal-arene interaction between
palladium and gold with these ligands, since in the case of
gold, the metal does not bind to the second aryl ring. The
resulting gold(I) complexes are at the same time robust and
highly active and, for these reasons, are among the most
commonly used catalysts in homogeneous gold(I) catalysis.
The rigid biaryl scaffold also allows the introduction of distal
functional groups that assist the catalysis in new ways as well
as chiral elements that control the folding of unsaturated
substrates.

Acknowledgements
Scheme 21. Application of chiral complex 110 in catalysis and total
synthesis.

We thank the Agencia Estatal de Investigación (AEI)/FEDER,
UE (CTQ2016-75960-P) and Caixa-Severo Ochoa predoctoral
fellowship to M.Z.), the European Research Council (Advanced Grant No. 835080), the AGAUR (2017 SGR 1257),
and CERCA Program/Generalitat de Catalunya for financial
support.

References

Scheme 22. Most favorable binding orientations for a)1,6-enynes 113
and b) 1,6-enyne 117.

interactions with the biphenyl scaffold of the ligand provided
further stabilization of the transition states and, in case of 1,6enynes 113, aryl-OMe interactions were also identified to be
important to define the stereocontrol.

Isr. J. Chem. 2020, 60, 1 – 14

[1] Y. Ito, M. Sawamura, T. Hayashi, J. Am. Chem. Soc. 1986, 108,
6405–6406.
[2] J. H. Teles, S. Brode, M. Chabanas, Angew. Chem. Int. Ed.
1998, 37, 1415–1518.
[3] E. Mizushima, K. Sato, T. Hayashi, M. Tanaka, Angew. Chem.
Int. Ed. 2002, 41, 4563–4565.
[4] A. S. K. Hashmi, T. M. Frost, J. W. Bats, J. Am. Chem. Soc.
2000, 122, 11553–11554.
[5] M. R. Luzung, J. P. Markham, F. D. Toste, J. Am. Chem. Soc.
2004, 126, 10858–10859.
[6] V. Mamane, T. Gress, H. Krause, A. Fürstner, J. Am. Chem. Soc.
2004, 126, 8654–8655.
[7] A. M. Echavarren, C. Nevado, Chem. Soc. Rev. 2004, 33, 431–
436.
[8] J. J. Kennedy-Smith, S. T. Staben, F. D. Toste, J. Am. Chem.
Soc. 2004, 126, 4526–4527.
[9] S. T. Staben, J. J. Kennedy-Smith, F. D. Toste, Angew. Chem.
Int. Ed. 2004, 43, 5350–5352.
[10] C. Nevado, A. M. Echavarren, Chem. Eur. J. 2005, 11, 3155–
3164.
[11] C. Ferrer, A. M. Echavarren, Angew. Chem. Int. Ed. 2006, 45,
1105–1109.
[12] S. Antoniotti, E. Genin, V. Michelet, J. P. Genê, J. Am. Chem.
Soc. 2005, 127, 9976–9977.
[13] A. Buzas, F. Gagosz, Org. Lett. 2006, 8, 515–518.
[14] E. Mizushima, T. Hayashi, M. Tanaka, Org. Lett. 2003, 5,
3349–3352.
[15] A. Fürstner, Chem. Soc. Rev. 2009, 38, 3208–3221.
[16] N. D. Shapiro, F. D. Toste, Synlett 2010, 2010, 675–691.

© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

www.ijc.wiley-vch.de

11

These are not the final page numbers! ��

Review
[17] C. Obradors, A. M. Echavarren, Acc. Chem. Res. 2014, 47, 902–
912.
[18] L. Fensterbank, M. Malacria, Acc. Chem. Res. 2014, 47, 953–
965.
[19] R. Dorel, A. M. Echavarren, Chem. Rev. 2015, 115, 9028–9072.
[20] D. P. Day, P. W. H. Chan, Adv. Synth. Catal. 2016, 358, 1368–
1384.
[21] J. G. Mayans, H. Armengol-Relats, P. Calleja, A. M. Echavarren, Isr. J. Chem. 2018, 58, 639–658.
[22] D. Pflästerer, A. S. K. Hashmi, Chem. Soc. Rev. 2016, 45,
1331–1367.
[23] Y. Wang, M. E. Muratore, A. M. Echavarren, Chem. Eur. J.
2015, 21, 7332–7339.
[24] D. Benitez, N. D. Shapiro, E. Tkatchouk, Y. Wang, W. A.
Goddard, F. D. Toste, Nat. Chem. 2009, 1, 482–486.
[25] J. P. Wolfe, S. L. Buchwald, Angew. Chem. Int. Ed. 1999, 38,
2413–2416.
[26] T. E. Barder, S. L. Buchwald, J. Am. Chem. Soc. 2007, 129,
5096–5101.
[27] H. Tomori, J. M. Fox, S. L. Buchwald, J. Org. Chem. 2000, 65,
5334–5341.
[28] R. Martin, S. L. Buchwald, Acc. Chem. Res. 2008, 41, 1461–
1473.
[29] K. Billingsley, S. L. Buchwald, J. Am. Chem. Soc. 2007, 129,
3358–3366.
[30] P. Pérez-Galán, N. Delpont, E. Herrero-Gómez, F. Maseras,
A. M. Echavarren, Chem. Eur. J. 2010, 16, 5324–5332.
[31] A. C. Sather, S. L. Buchwald, Acc. Chem. Res. 2016, 49, 2146–
2157.
[32] R. Dorel, C. P. Grugel, A. M. Haydl, Angew. Chem. Int. Ed.
2019, 17118–17129.
[33] B. T. Ingoglia, C. C. Wagen, S. L. Buchwald, Tetrahedron 2019,
75, 4199–4211.
[34] S. Porcel, A. M. Echavarren, Angew. Chem. 2007, 119, 2726–
2730.
[35] P. K. Dhondi, P. Carberry, L. B. Choi, J. D. Chisholm, J. Org.
Chem. 2007, 72, 9590–9596.
[36] P. K. Dhondi, J. D. Chisholm, Org. Lett. 2006, 8, 67–69.
[37] J. W. Faller, D. G. D’Alliessi, Organometallics 2003, 22, 2749–
2757.
[38] J. Haider, K. Kunz, U. Scholz, Adv. Synth. Catal. 2004, 346,
717–722.
[39] C. Nieto-Oberhuber, S. López, A. M. Echavarren, J. Am. Chem.
Soc. 2005, 127, 6178–6179.
[40] C. Nieto-Oberhuber, M. P. Muñoz, S. López, E. Jiménez-Núñez,
C. Nevado, E. Herrero-Gómez, M. Raducan, A. M. Echavarren,
Chem. Eur. J. 2006, 12, 1677–1693.
[41] C. Nieto-Oberhuber, S. López, E. Jiménez-Núñez, A. M.
Echavarren, Chem. Eur. J. 2006, 12, 5916–5923.
[42] C. Nieto-Oberhuber, M. P. Muñoz, E. Buñuel, C. Nevada, D. J.
Cárdenas, A. M. Echavarren, Angew. Chem. Int. Ed. 2004, 43,
2402–2406.
[43] M. Paz Muñoz, J. Adrio, J. C. Carretero, A. M. Echavarren,
Organometallics 2005, 24, 1293–1300.
[44] C. Nieto-Oberhuber, P. Pérez-Galán, E. Herrero-Gómez, T.
Lauterbach, C. Rodríguez, S. López, C. Bour, A. Rosellón, D. J.
Cárdenas, A. M. Echavarren, J. Am. Chem. Soc. 2008, 130,
269–279.
[45] R. Dorel, P. R. McGonigal, A. M. Echavarren, Angew. Chem.
Int. Ed. 2016, 55, 11120–11123.
[46] A. J. Athans, J. B. Briggs, W. Jia, G. P. Miller, J. Mater. Chem.
2007, 17, 2636–2641.
[47] R. Dorel, A. M. Echavarren, Eur. J. Org. Chem. 2017, 2017,
14–24.

Isr. J. Chem. 2020, 60, 1 – 14

[48] J. E. Anthony, Chem. Rev. 2006, 106, 5028–5048.
[49] M. Bendikov, F. Wudl, D. F. Perepichka, Tetrathiafulvalenes,
Oligoacenenes, and Their Buckminsterfullerene Derivatives:
The Brick and Mortar of Organic Electronics, 2004.
[50] J. E. Anthony, Angew. Chem. Int. Ed. 2008, 47, 452–483.
[51] R. Zuzak, R. Dorel, M. Krawiec, B. Such, M. Kolmer, M.
Szymonski, A. M. Echavarren, S. Godlewski, ACS Nano 2017,
11, 9321–9329.
[52] R. Zuzak, R. Dorel, M. Kolmer, M. Szymonski, S. Godlewski,
A. M. Echavarren, Angew. Chem. Int. Ed. 2018, 57, 10500–
10505.
[53] C. H. M. Amijs, C. Ferrer, A. M. Echavarren, Chem. Commun.
2007, 698–700.
[54] Z. Shi, C. He, J. Org. Chem. 2004, 69, 3669–3671.
[55] M. T. Reetz, K. Sommer, Eur. J. Org. Chem. 2003, 3485–3496.
[56] L. Zhang, L. Chang, H. Hu, H. Wang, Z. J. Yao, S. Wang,
Chem. Eur. J. 2014, 20, 2925–2932.
[57] C. Ferrer, C. H. M. Amijs, A. M. Echavarren, Chem. Eur. J.
2007, 13, 1358–1373.
[58] W. Damm, J. Dickhaut, F. Wetterich, B. Giese, Tetrahedron
Lett. 1993, 34, 431–434.
[59] A. H. Jackson, P. Smith, Tetrahedron 1968, 24, 2227–2239.
[60] L. Zhang, Y. Wang, Z. J. Yao, S. Wang, Z. X. Yu, J. Am. Chem.
Soc. 2015, 137, 13290–13300.
[61] C. Ferrer, A. Escribano-Cuesta, A. M. Echavarren, Tetrahedron
2009, 65, 9015–9020.
[62] M. S. Kirillova, F. M. Miloserdov, A. M. Echavarren, Org.
Chem. Front. 2018, 5, 273–287.
[63] M. S. Kirillova, M. E. Muratore, R. Dorel, A. M. Echavarren, J.
Am. Chem. Soc. 2016, 138, 3671–3674.
[64] F. M. Miloserdov, M. S. Kirillova, M. E. Muratore, A. M.
Echavarren, J. Am. Chem. Soc. 2018, 140, 5393–5400.
[65] E. Jiménez-Núñez, M. Raducan, T. Lauterbach, K. Malawi,
C. R. Solorio, A. M. Echavarren, Angew. Chem. Int. Ed. 2009,
48, 6152–6155.
[66] P. Calleja, Ó. Pablo, B. Ranieri, M. Gaydou, A. Pitaval, M.
Moreno, M. Raducan, A. M. Echavarren, Chem. Eur. J. 2016,
22, 13613–13618.
[67] D. Lebœuf, M. Gaydou, Y. Wang, A. M. Echavarren, Org.
Chem. Front. 2014, 1, 759–764.
[68] A. Fürstner, P. Hannen, Chem. Eur. J. 2006, 12, 3006–3019.
[69] M. Gaydou, R. E. Miller, N. Delpont, J. Ceccon, A. M.
Echavarren, Angew. Chem. Int. Ed. 2013, 52, 6396–6399.
[70] E. Jiménez-Núñez, C. K. Claverie, C. Nieto-Oberhuber, A. M.
Echavarren, Angew. Chem. Int. Ed. 2006, 45, 5452–5455.
[71] S. Ferrer, A. M. Echavarren, Org. Lett. 2018, 20, 5784–5788.
[72] C. R. Solorio-Alvarado, A. M. Echavarren, J. Am. Chem. Soc.
2010, 132, 11881–11883.
[73] F. Q. Shi, X. Li, Y. Xia, L. Zhang, Z. X. Yu, J. Am. Chem. Soc.
2007, 129, 15503–15512.
[74] M. Mato, I. Martín-Torres, B. Herlé, A. M. Echavarren, Org.
Biomol. Chem. 2019, 17, 4216–4219.
[75] M. Mato, C. García-Morales, A. M. Echavarren, ChemCatChem
2019, 11, 53–72.
[76] R. Hoffmann, Tetrahedron Lett. 1970, 11, 2907–2909.
[77] O. A. McNamara, A. R. Maguire, Tetrahedron 2011, 67, 9–40.
[78] L. Batiste, A. Fedorov, P. Chen, Chem. Commun. 2010, 46,
3899–3901.
[79] B. Herlé, P. M. Holstein, A. M. Echavarren, ACS Catal. 2017, 7,
3668–3675.
[80] M. Mato, B. Herlé, A. M. Echavarren, Org. Lett. 2018, 20,
4341–4345.
[81] C. R. Solorio-Alvarado, Y. Wang, A. M. Echavarren, J. Am.
Chem. Soc. 2011, 133, 11952–11955.

© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

www.ijc.wiley-vch.de

12

These are not the final page numbers! ��

Review
[82] Y. Wang, P. R. McGonigal, B. Herlé, M. Besora, A. M.
Echavarren, J. Am. Chem. Soc. 2014, 136, 801–809.
[83] Y. Wang, M. E. Muratore, Z. Rong, A. M. Echavarren, Angew.
Chem. Int. Ed. 2014, 53, 14022–14026.
[84] X. Yin, M. Mato, A. M. Echavarren, Angew. Chem. Int. Ed.
2017, 56, 14591–14595.
[85] R. F. Angawi, W. M. Alarif, R. I. Hamza, F. A. Badria, S. E. N.
Ayyad, Helv. Chim. Acta 2014, 97, 1388–1395.
[86] X. Q. Yu, W. F. He, D. Q. Liu, M. T. Feng, Y. Fang, B. Wang,
L. H. Feng, Y. W. Guo, S. C. Mao, Phytochemistry 2014, 103,
162–170.
[87] C. K. Kim, J. K. Woo, S. H. Kim, E. Cho, Y. J. Lee, H. S. Lee,
C. J. Sim, D. C. Oh, K. B. Oh, J. Shin, J. Nat. Prod. 2015, 78,
2814–2821.
[88] W. H. Jiao, G. H. Shi, T. T. Xu, G. D. Chen, B. Bin Gu, Z.
Wang, S. Peng, S. P. Wang, J. Li, B. N. Han, J. Nat. Prod. 2016,
79, 406–411.
[89] X. Yin, G. Zuccarello, C. García-Morales, A. M. Echavarren,
Chem. Eur. J. 2019, 9485–9490.
[90] M. Mato, A. M. Echavarren, Angew. Chem. Int. Ed. 2019, 58,
2088–2092.
[91] S. Kaye, J. M. Fox, F. A. Hicks, S. L. Buchwald, Adv. Synth.
Catal. 2001, 343, 789–794.
[92] U. Christmann, R. Vilar, A. J. P. White, D. J. Williams, Chem.
Commun. 2004, 4, 1294–1295.
[93] U. Christmann, D. A. Pantazis, J. Benet-Buchholz, J. E.
McGrady, F. Maseras, R. Vilar, J. Am. Chem. Soc. 2006, 128,
6376–6390.
[94] E. Herrero-Gómez, C. Nieto-Oberhuber, S. López, J. BenetBuchholz, A. M. Echavarren, Angew. Chem. Int. Ed. 2006, 45,
5455–5459.
[95] Q. S. Li, C. Q. Wan, R. Y. Zou, F. B. Xu, H. Bin Song, X. J.
Wan, Z. Z. Zhang, Inorg. Chem. 2006, 45, 1888–1890.
[96] R. E. M. Brooner, R. A. Widenhoefer, Angew. Chem. Int. Ed.
2013, 52, 11714–11724.
[97] M. Espina, I. Rivilla, A. Conde, M. M. Díaz-Requejo, P. J.
Pérez, E. Álvarez, R. Fernández, J. M. Lassaletta, Organometallics 2015, 34, 1328–1338.
[98] F. Grande-Carmona, J. Iglesias-Sigüenza, E. Álvarez, E. Díez,
R. Fernández, J. M. Lassaletta, Organometallics 2015, 34,
5073–5080.
[99] J. Carreras, A. Pereira, M. Zanini, A. M. Echavarren, Organometallics 2018, 37, 3588–3597.
[100] N. A. Barnes, K. R. Flower, S. M. Godfrey, P. A. Hurst, R. Z.
Khan, R. G. Pritchard, CrystEngComm 2010, 12, 4240–4251.
[101] O. Bin Shawkataly, C. P. Goh, A. Tariq, I. A. Khan, H. K. Fun,
M. M. Rosli, PLoS One 2015, 10, 1–15.
[102] O. Bin Shawkataly, A. Tariq, I. A. Khan, C. S. Yeap, H. K. Fun,
Acta Crystallogr. Sect. E 2011, 67, DOI 10.1107/
S1600536811008646.
[103] R. Jothibasu, H. V. Huynh, Chem. Commun. 2010, 46, 2986–
2988.

Isr. J. Chem. 2020, 60, 1 – 14

[104] Y. Wang, Z. Wang, Y. Li, G. Wu, Z. Cao, L. Zhang, Nat.
Commun. 2014, 5, 3470.
[105] Z. Wang, Y. Wang, L. Zhang, J. Am. Chem. Soc. 2014, 136,
8887–8890.
[106] X. Li, Z. Wang, X. Ma, P. N. Liu, L. Zhang, Org. Lett. 2017, 19,
5744–5747.
[107] Z. Wang, A. Ying, Z. Fan, C. Hervieu, L. Zhang, ACS Catal.
2017, 7, 3676–3680.
[108] H. Wang, T. Li, Z. Zheng, L. Zhang, ACS Catal. 2019, 9,
10339–10342.
[109] S. Liao, A. Porta, X. Cheng, X. Ma, G. Zanoni, L. Zhang,
Angew. Chem. Int. Ed. 2018, 57, 8250–8254.
[110] T. Li, Y. Yang, B. Li, X. Bao, L. Zhang, Org. Lett. 2019, 21,
7791–7794.
[111] T. Li, L. Zhang, J. Am. Chem. Soc. 2018, 140, 17439–17443.
[112] W. Zi, F. Dean Toste, Chem. Soc. Rev. 2016, 45, 4567–4589.
[113] Y. Li, W. Li, J. Zhang, Chem. Eur. J. 2017, 23, 467–512.
[114] Y. M. Wang, A. D. Lackner, F. D. Toste, Acc. Chem. Res. 2014,
47, 889–901.
[115] R. L. Lalonde, B. D. Sherry, E. J. Kang, F. D. Toste, J. Am.
Chem. Soc. 2007, 129, 2452–2453.
[116] M. J. Johansson, D. J. Gorin, S. T. Staben, F. D. Toste, J. Am.
Chem. Soc. 2005, 127, 18002–18003.
[117] H. Teller, M. Corbet, L. Mantilli, G. Gopakumar, R. Goddard,
W. Thiel, A. Fürstner, J. Am. Chem. Soc. 2012, 134, 15331–
15342.
[118] G. L. Hamilton, E. J. Jang, M. Mba, F. D. Toste, Science 2007,
317, 496–499.
[119] P. Zhang, C. Tugny, J. Meijide Suárez, M. Guitet, E. Derat, N.
Vanthuyne, Y. Zhang, O. Bistri, V. Mouriès-Mansuy, M.
Ménand, Chem 2017, 3, 174–191.
[120] P. T. Bohan, F. Dean Toste, J. Am. Chem. Soc. 2017, 139,
11016–11019.
[121] X. Cheng, Z. Wang, C. D. Quintanilla, L. Zhang, J. Am. Chem.
Soc. 2019, 141, 3787–3791.
[122] Z. Wang, C. Nicolini, C. Hervieu, Y. F. Wong, G. Zanoni, L.
Zhang, J. Am. Chem. Soc. 2017, 139, 16064–16067.
[123] K. Yavari, P. Aillard, Y. Zhang, F. Nuter, P. Retailleau, A.
Voituriez, A. Marinetti, Angew. Chem. Int. Ed. 2014, 53, 861–
865.
[124] Y. Wang, P. Zhang, X. Di, Q. Dai, Z. M. Zhang, J. Zhang,
Angew. Chem. Int. Ed. 2017, 56, 15905–15909.
[125] G. Zuccarello, J. G. Mayans, I. Escofet, D. Scharnagel, M. S.
Kirillova, A. H. Pérez-Jimeno, P. Calleja, J. R. Boothe, A. M.
Echavarren, J. Am. Chem. Soc. 2019, 141, 11858–11863.

Manuscript received: December 21, 2019
Revised manuscript received: January 24, 2020
Version of record online: February 24, 2020

© 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

www.ijc.wiley-vch.de

13

These are not the final page numbers! ��

REVIEW
G. Zuccarello, M. Zanini, A. M. Echavarren*
1 – 14
Buchwald-Type Ligands on Gold(I)
Catalysis