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"This is the peer reviewed version of the following article: Green Chem. 2014, 16, 1552-1559, which has been published in final
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Conversion of Oxiranes and CO2 to Organic Cyclic Carbonates using a
Recyclable, Bifunctional Polystyrene-Supported Organocatalyst
Christopher J. Whiteoak,a Andrea H. Henseler,a Carles Ayats,a Arjan W. Kleij,*a,b Miquel A. Pericàs*a,c
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Received (in XXX, XXX) Xth XXXXXXXXX 20XX, Accepted Xth XXXXXXXXX 20XX
DOI: 10.1039/b000000x
The development of a heterogeneous one-component bifunctional catalyst system able to catalyse the
conversion of carbon dioxide and oxiranes to organic cyclic carbonates at low temperature (45 ºC) is
reported. The bifunctional system can be easily recycled and reactivated when required. When compared
with other heterogeneous organocatalysts for the same transformation, the reported catalyst is active at
much milder temperatures, thus emphasising the optimal sustainability profile of the new catalyst system.

Introduction

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The use of carbon dioxide (CO2) in chemical synthesis is attracting
significant interest as a result of growing concerns about the
environmental impact of this greenhouse gas, but also because CO2
as a potential carbon source is inexpensive, widely available and
non-toxic.1-4 The principal limitation to the use of CO2 as a carbon
source is its high kinetic stability and therefore chemical processes
utilising CO2 as feedstock usually require elevated operating
temperatures limiting overall sustainability. An ideal CO2 utilising
process should emit less CO2 than it uses, hence there is a desire
for the use of lower reaction temperatures as energy generation
required for heating results in emissions of CO2. To date the
development of CO2 utilising processes which are operative at
ambient conditions is and continues to be a huge challenge. The
combination of CO2 and a reagent with high intrinsic energy can
facilitate the conversion of CO2 and indeed, one of the most
developed reactions for the conversion of CO2 into value-added
organic matter is the ring-expansion addition reaction of CO2 to
oxiranes (Scheme 1).

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Scheme 1 Ring-expansion addition reaction of CO2 to oxiranes.
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In the simplest case, this reaction proceeds in the presence of
only a catalytic amount of a tetrabutylammonium halide salt at 120
ºC to yield the desired cyclic organic carbonates.5 In addition to
utilising a reagent with high intrinsic energy, efficient catalytic
systems can be employed to further enhance the reaction kinetics
and for the aforementioned ring-expansion addition reaction of
CO2 to oxiranes there have been extensive reports of catalytic
systems able to mediate this conversion.6,7 The use of a Lewis acid
catalyst in addition to a nucleophilic co-catalyst permits the use of
more sustainable reaction conditions and over recent years several
Lewis acidic catalysts have been reported to be active at ambient
temperatures based on Al,8 Zn9 and Fe.10
In contrast to the number of metal-based catalyst systems
reported, the number of organocatalyst systems reported is
2 | Green Chem., 2013, 15, 00–00

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relatively scarce and this is most probably due to their reduced
substrate activation potential. As a result, most of the reported
examples typically require the use of unfavourable elevated
temperatures (>100 ºC) challenging the sustainability and hence
applicability of these catalysts. Previously, in our laboratory we
have developed an organocatalyst system active at more
favourable temperatures (2545 ºC). We reported that
commercially available 1,2,3-tris-hydroxybenzene (pyrogallol) in
combination with tetrabuylammonium iodide (TBAI) is able to
convert CO2 and a variety of oxiranes into the corresponding
organic cyclic carbonates at ambient temperature and pCO2 = 1.0
MPa.11 The mode of action of this catalyst system was elucidated
through DFT calculations and it was found that an extended
hydrogen-bonding network is responsible for more efficient
stabilisation of reaction intermediates, making the oxiranes more
susceptible towards ring opening by the co-catalytic halide
nucleophile. This binary catalyst system showed non-optimal
recycling potential and in order to further increase the
sustainability of this catalyst system we decided to pursue the
possibility to develop a heterogenised system by anchoring the
pyrogallol unit onto a suitable support.
Immobilisation of catalysts allows facile separation from the
reaction mixture by simple filtration, avoiding tedious
isolation/purification steps and as a result allows for catalyst
recycling. The main benefits of polystyrene (PS) as supporting
material include its high chemical, thermal, and mechanical
stability and the fact that the support allows for facile chemical
modification. Furthermore, heterogenised catalysts combine the
properties of their homogeneous analogues with the key features
of heterogeneous catalysts and are suitable for continuous flow
processes avoiding co-elution of the catalyst.12-14 Recently, part of
us had considerable success in realising polystyrene supported
organocatalyst systems for a variety of catalytic applications 15-18
and thus we decided to use these favourable support features to
develop a heterogenised and more sustainable catalyst based on the
aforementioned pyrogallol.
There have been several reports of immobilised organocatalyst
systems for the conversion of oxiranes and CO2 to organic cyclic
carbonates including immobilised ionic liquids,19 bio-polymers20
and immobilised amino acids21 amongst others. Unfortunately
though, as mentioned earlier, most of these catalyst systems require
operating temperatures above 100 ºC which challenges their
This journal is © The Royal Society of Chemistry 2013

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Table 1 Conversion of 1,2-epoxyhexane 4 into its corresponding cyclic
carbonate 4a using PS-Cat 1.a

overall sustainability. Herein, we report the synthesis and
application of more sustainable and recyclable catalyst systems
based on polystyrene supported pyrogallol for the conversion of
CO2 and oxiranes into cyclic organic carbonates under attractive
conditions.

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Entry
1
2
3
4

PS-Cat

1
1
1

Run

1
2
3

Yield (%)b
24
78
48
30

TONc

39
24
15

a

reaction conditions: 1,2-epoxyhexane (1.0 g, 9.98 mmol), PS-Cat 1 (2.0
mol%), TBAI (2.0 mol%), 45 ºC, pCO2 = 1.0 MPa, 18 h. b Isolated yield. c
TON is defined as turnover per pyrogallol unit.

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Scheme 2 Synthesis of the PS-Cat 1. Reagents and conditions: (i) HBr,
AcOH, 16 h, reflux, 76%; (ii) NaHCO3 (2.4 eq.), propargyl bromide
(2.0 eq.), DMF, 14 h, rt, 64%; (iii) azidomethyl polystyrene, Cu-cat
(3 mol%), DMF/THF (1:1), 1.5 h, 80 ºC, 200 W.
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Results and discussion
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The synthesis of the initial PS-Cat 1 could be achieved in three
simple steps from commercially available starting materials and is
shown
in
Scheme
2.
Demethylation
of
3,4,5trimethoxyphenylacetic acid 1 with hydrobromic acid afforded
3,4,5-trihydroxyacetic acid 2, which was subsequently converted
into the corresponding propargylated product 3 by reaction with
propargyl bromide. PS-Cat 1 (f = 1.0 mmol·g-1) was then obtained
from the reaction of azidomethyl polystyrene and 3 via a coppercatalysed alkyne azide cycloaddition (CuAAC) reaction (See ESI†
for full procedures and details).22,23
When PS-Cat 1 was used as catalyst for the conversion of 1,2epoxyhexane, our benchmark substrate, at a loading of 2 mol% in
the presence of TBAI (2 mol%) at 45 ºC and a CO2 pressure of 1.0
MPa, we observed a conversion of 78% after 18 hours (Table 1,
entry 2). The binary catalyst system could be easily separated from
the product by the addition of diethyl ether (with NBu4I being
rather insoluble in this solvent) and subsequent filtration. After
removal of the solvent and unreacted substrate from the filtrate
under reduced pressure, pure organic cyclic carbonate was
obtained. In comparison, under these conditions TBAI alone at a
loading of 2 mol% allows for a much lower isolated yield of 24%
(Table 1, entry 1). The recovered catalyst system was then used in
a second run. Unfortunately, the activity of the catalyst system was
reduced in the second run, whereby only 48% product yield was
obtained (Table 1, entry 3). The catalyst system was recovered and
used again in a third run in which a further reduction in isolated
product was observed (30%, Table 1, entry 4).

This journal is © The Royal Society of Chemistry 2013

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This reduction in catalytic activity was coupled with a visible
darkening of the PS-support as more runs were carried out. In order
to investigate this darkening we reacted pyrogallol, TBAI and 1,2epoxyhexane stoichiometrically using a minimal amount of
dichloromethane as solvent. After 18 hours the darkened reaction
mixture was analysed by 1H NMR spectroscopy, where it was
observed that the spectrum had changed from that of the initial one.
Isolation of the reaction products indicated that the pyrogallol had
reacted with TBAI to yield an ammonium phenolate salt and iodide
had reacted with the 1,2-epoxyhexane resulting in the formation of
a halohydrin species (see Scheme 3).

Scheme 3 Products arising from the reaction of pyrogallol, 1,2epoxyhexane and TBAI.

We propose that this reaction may be a catalyst deactivation
route as the hydrogen-bonding network decreases and halide
nucleophile concentration becomes depleted over successive runs
as a result. PS-Cat 1 contains a triazole linker as a result of the
CuAAC reaction involved in the PS functionalisation step. It was
envisaged that reaction of this triazole linker with methyl iodide
could result in a one-component bifunctional catalyst system (cf.,
PS-Cat 2, Scheme 4) with a higher stability than that of the binary
catalyst system described above.

Green Chem., 2013, 15, 00–00 | 3

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4 suggesting the involvement of the 1,2,3-trihydroxybenzene
moiety in the catalysis reaction (Table 2, entries 1 and 2). It can
also be seen that the decrease in activity for bifunctional PS-Cat 2
is slower than that observed for the binary catalyst system PS-Cat
1. A reduction in the isolated product yield to 48% already occurs
in run 2 using the PS-Cat 1/TBAI binary catalyst system, while in
the case of the bifunctional PS-Cat 2 a similar decrease in product
yield is noted in the fourth run and thus PS-Cat 2 retains activity
for a longer period of time. Elemental analysis obtained for the PSCat 2 system before use (11.73% I) and after 4 runs (2.45% I)
indicates that the loss of activity should be ascribed to the reduction
in the halide nucleophile that is required for the ring opening of the
oxirane during the conversion into its carbonate. A similar iodine
elemental analysis performed on PS-Cat 4 showed that in this case
no decrease in the halide occurs with reuse, and this suggests that
the adjacent pyrogallol unit facilitates this process in PS-Cat 2
(e.g., through a hydrogen-bond assisted Herzig-Meyer
demethylation).

Scheme 4 Synthesis of PS-Cat 2 and PS-Cat 4. Reagents and conditions:
(i) MeI (5.0 eq.), CH3CN, 48 h, 75 ºC.
5

Table 2 Conversion of 1,2-epoxyhexane 4 into its corresponding cyclic
carbonate 4a using PS-Cat 2 and PS-Cat 4.a

Entry
1
2
3
4
5
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20

25

PS-Cat
4
2
2
2
2

Run

1
2
3
4

Yield (%)b
20
84
76
62
48

TONc
5
21
19
16
12

a

Reaction conditions: 1,2-epoxyhexane (1.0 g, 9.98 mmol), PS-Cat 2 or
PS-Cat 4 (4.0 mol%), 45 ºC, pCO2 = 1.0 MPa, 18 h. b Isolated yield. c
TON is defined as turnover per pyrogallol unit.

The remote position of a potential triazolium ion from the 1,2,3trihydroxybenzene site is likely to make a one-component
bifunctional catalyst more stable toward the aforementioned
decomposition compared with the binary catalyst system. Reaction
of PS-Cat 1 with methyl iodide in acetonitrile resulted in the
formation of PS-Cat 2 (Scheme 4). A support material terminated
in a phenyl-triazole unit, PS-3, was also prepared for comparison
and reacted with methyl iodide in the same manner to realise PSCat 4 which was used to ensure that any activity observed is not
the result of catalysis involving the co-catalyst only.
As may be expected, the one-component PS-Cat 2 requires a
higher catalyst loading in order to attain a similar activity to that of
the binary system containing both but separate PS-Cat 1 and TBAI
(Table 1, entry 2 vs. Table 2, entry 2). The bifunctional PS-Cat 2
shows a fourfold higher yield under these conditions than PS-Cat
4 | Green Chem., 2013, 15, 00–00

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Scheme 5 Synthesis of PS-Cat 5. Reagents and conditions: (i) 3 (0.2 eq.),
Cu-cat (3 mol%), DMF/THF (1:1), 1.5 h, 80 ºC, 200 W; (ii)
Phenylacetylene (1.2 eq.), Cu-cat (3 mol%), DMF/THF (1:1), 1.5 h, 80 ºC,
200 W; (iii) MeI (5 eq.), CH3CN, 48 h, 75 ºC.

In an attempt to realise a PS-supported catalyst system that does
not suffer from deactivation problems, we planned to prepare a
bifunctional resin where the triazolium and pyrogallol units could
be linked to distinct positions along the polymer backbone. This
could be easily brought into practice as a result of the nondiscriminating nature of CuAAC reactions. Thus, even the relative
proportions of the two desired functional units could be in principle
controlled by performing on the same azido-functionalized
polymer two sequential CuAAC reactions with the minor, limiting
unit being introduced first. We accordingly devised a
straightforward synthetic protocol for the preparation of a resin
where the PS-supported 1,2,3-trihydroxybenzene containing
moieties and the other units (cf., red and green parts in Scheme 5)
existed in an optimal 1:4 ratio. This could be brought into practice
through the sequence shown in Scheme 5, where a final treatment
This journal is © The Royal Society of Chemistry 2013

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with methyl iodide leads to PS-Cat 5. It is interesting to note that
this versatile methodology may have wider applicability as it can
be applied to the preparation of other types of bifunctional
heterogeneous catalyst systems whereby the inclusion of different
catalytic moieties on the same PS support is required. Even in the
case that the triazolium moieties linking the 1,2,3trihydroxybenzene units to the polystyrene backbone suffered a
decomposition similar to the one observed in PS-Cat 2,24 the more
abundant phenyltriazolium units should remain stable with time (as
observed with PS-Cat 4) and preserve better the catalytic activity
of PS-Cat 5. Indeed, PS-Cat 5 (4 mol%) maintains its activity
levels for a longer period of time than PS-Cat 2, whilst the
reduction in the number of pyrogallol units in PS-Cat 5 (from 4.0
to 0.8 mol%) only leads to a modest reduction in the overall
activity, suggesting that the amount of halide nucleophile present
in PS-Cat 2 is indeed limiting the overall activity. An appreciable
reduction in activity of PS-Cat 5 only started to occur after five
runs (Fig. 1).

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Fig. 1 Recycling of bifunctional PS-Cat 5 in the synthesis of 4a.
Conditions: 1,2-epoxyhexane (1.0 g, 9.98 mmol), PS-Cat 5 (4.0 mol%), 45
ºC, pCO2 = 1.0 MPa, 18 h. Note that 4 mol% of “iodide” based PS
supported catalyst only gives 20% yield, cf. Table 2, entry 1. The catalyst
was reactivated after run 6.

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At this point, the support had slightly darkened in colour, but
less significantly than observed in the case of the binary couple PSCat 2/TBAI. Importantly, after a regenerative treatment of PS-Cat
5 with methyl iodide, the initial activity was virtually recovered
(Fig. 1, run 7) and the supported catalyst regained a pale brown
colour. The same sample of PS-Cat 5 was used in 11 consecutive
runs giving a total of 938 turnovers/1,2,3-trihydroxybenzene unit
which is significantly higher than those that may be obtained with
PS-Cat 1 or PS-Cat 2.
The bifunctional PS-Cat 5 was also studied for the conversion
of other substrates.25 In these experiments the supported catalyst
was used to convert one substrate and then recycled in order to

This journal is © The Royal Society of Chemistry 2013

convert further substrates. Table 3 summarises the results obtained
from this study. Propylene oxide (5), epichlorohydrin (6) and 1,2epoxy-5-hexene (7) could be successively converted (Table 3,
entries 13) into their respective organic carbonates 5a-7a with
excellent isolated yields. The catalyst system was then further
challenged by using styrene oxide 8 (Table 3, entry 4). This
substrate was found to be more sluggish using the homogeneous
version of the pyrogallol-based catalyst system reported
previously.11 The isolated yield of the carbonate product 8a (53%)
was lower in this case but in the same order of magnitude as for
the homogeneously catalysed reaction. To check if this reduced
yield was a result of deactivation of the catalyst system PS-Cat 5,
propylene oxide (5) was then again tested as substrate and the
isolated yield proved to be only slightly lower (89%) than at the
beginning of the recycling experiment (Table 3, entry 1 versus
entry 5).
As there was a small reduction in the yield it was decided to
reactivate the support by reaction with methyl iodide before further
use (after run 5, Table 3). With the intention of increasing the
obtained yield of the organic cyclic carbonate from styrene oxide
we decided to increase the operating temperature to 65 ºC (entry
6), which is still significantly lower than the temperatures reported
for other heterogeneous organocatalyst systems. At this higher
temperature an almost quantitative yield of the organic cyclic
carbonate product was obtained. This result prompted us to
challenge the catalyst system still further, by attempting to convert
an internal oxirane (entries 7 and 8). Internal oxiranes have been
shown to be difficult substrates to convert and we chose the
simplest example for our study, trans-2,3-epoxybutane. At 65 ºC a
low yield of only 8% was achieved, but upon increasing the
temperature and time of the reaction we were able to obtain up to
18% yield. Although this yield may not appear significant, it
should be noted that most metalbased catalyst systems are unable
to mediate efficient conversion of this substrate. We also noted that
although the starting material was 100% pure trans-2,3epoxybutane, at the higher temperature there was a significant loss
of configuration in the product (up to 18% cis-carbonate was
obtained). This behaviour has been studied before using an
iron(III) amino-triphenolate based catalyst system and was
suggested to arise from different ring-closure mechanisms.26
We then also investigated the use of some more challenging
internal epoxides (Table 3, entries 9-14). The cyclic epoxides of
entries 9 and 10 were, as expected, only converted to a minor
extent (12 and 15% yields, respectively) in line with previous
reports that internal epoxides generally require highly potent
(metal) catalysts and more harsh reaction conditions.10,26,27
Hereafter, the benzyl glycidyl ether substrate (entry 11) could be
cleanly converted in high yield (89%) and also the rarely reported
conversion of indene oxide28 proceeded smoothly (entry 12, >99%
yield).

Green Chem., 2013, 15, 00–00 | 5

Table 3 Reuse of bifunctional PS-Cat 5 with different substrates.a

6 | Green Chem., 2013, 15, 00–00

This journal is © The Royal Society of Chemistry 2013

Substrate

Product

Yield (%)b

Run

T (ºC)

1

45

96

2

45

94

3

45

91

4

45

53

5c

45

89

6

65

98

7d

65

8e

8f

85

18g

9

85

12

10

85

15

11

45

89

12

85

>99

This journal is © The Royal Society of Chemistry 2013

Green Chem., 2013, 15, 00–00 | 7

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72
50

14h

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i

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a

5

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Reaction conditions: substrate (10.0 mmol), PS-Cat 5 (8.0 mol%), pCO2
= 1.0 MPa, 18 h. b Isolated yield. c Reactivation of PS-Cat 5 with methyl
iodide done after this run. d 42 h. e Traces of cis-product present. f 66 h. g
Product mixture contained 82% trans- and 18% cis-carbonate by 1H NMR
analysis. h The catalyst was reactivated with MeI before this run was carried
out. i A mixture of products was obtained, for details see the ESI†.

In order to test whether the catalyst had lost some of its activity,
propylene oxide was then used as substrate (entry 13) and this
afforded a 72% yield of the carbonate product being lower than
those reported in entries 1 and 5. Therefore, before further use the
PS-Cat 5 was first reactivated again using MeI.29 As a final
substrate in the series, phenyl glycidol (entry 14) was evaluated;
unlike in the case of glycidol25 the product of this experiment could
be isolated (see ESI for details). However, 1H NMR analysis and
by comparison with authentic samples prepared individually it is
clear that the reaction proceeds with much lower selectivity, and
indications were found for the formation of polyols, i.e. ringopening of this epoxide substrate by adventitious water had
occurred.
Nonetheless, the results reported in Table 3 clearly demonstrate
the unique potential of this supported, bifunctional catalyst PSCAT 5 for the conversion of a variety of different epoxides into
their cyclic carbonates using a single catalyst batch.

Typical procedure for organic cyclic carbonate synthesis from
oxiranes and CO2
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Conclusions
In summary, we have reported an efficient PS supported
organocatalyst system based on a pyrogallol (i.e., 1,2,3trihydroxybenzene) scaffold for the conversion of CO2 and
oxiranes into organic cyclic carbonates which is active at
significantly lower temperatures (45 ºC) than those previously
reported for other heterogeneous organocatalyst systems (>100
ºC). This catalyst system represents an improvement of our
previously reported pyrogallol catalyst and is an example of how
click-chemistry can be utilised for the immobilisation of an
organocatalyst onto functionalised-PS. The reported catalyst
system (PS-Cat 5) can also be recycled and upon loss of activity
can be easily regenerated by reaction with methyl iodide. In
addition, we have exemplified the potential for inclusion of
different catalytic moieties on the same PS support, which may
have wider applicability for the realisation of other heterogeneous
catalysts which require multiple catalytic sites. It therefore marks
this versatile catalyst preparation procedure as highly attractive for
optimising structure-reactivity features of new catalyst systems
with an improved sustainability footprint.

8 | Green Chem., 2013, 15, 00–00

1,2-epoxyhexane (1.0 g, 10.1 mmol) was placed in a 30 mL
stainless steel autoclave with a PS-Cat (2.0 mol%) and TBAI (2.0
mol%) (i.e., binary catalyst system) or PS-Cat 5 (4.0 mol%) (i.e.,
the bifunctional catalyst system). The autoclave was then subjected
to three cycles of pressurisation and depressurisation with carbon
dioxide (5 MPa), before final stabilisation of the pressure to 10
MPa. The autoclave was sealed and heated to 45 ºC and left
stirring. After 18 hours the reaction mixture was suspended in
diethyl ether (20 mL) and filtered. The catalyst system was further
washed with diethyl ether (3 × 10 mL) and the solvent removed
from the combined organic filtrates under reduced pressure to yield
the organic cyclic carbonate product. The identity of the organic
cyclic carbonate product was confirmed by comparison to
literature data. The collected catalyst system was used again in
subsequent catalytic runs. 1H and 13C NMR and IR spectra of the
organic cyclic carbonate products can be found in the Electronic
Supplementary Information (ESI). Below a listing of analytical
data is presented of the obtained cyclic carbonates 4a13a.
4-Butyl-1,3-dioxolan-2-one (4a).30 1H NMR (400 MHz,
CDCl3) δ 4.79 – 4.62 (m, 1H), 4.52 (dd, 2JHH = 8.1 and 3JHH = 8.1
Hz, 1H), 4.08 (dd, 2JHH = 8.1 and 3JHH = 7.3 Hz, 1H), 1.90 – 1.58
(m, 2H), 1.53 – 1.25 (m, 4H), 0.92 (t, 3JHH = 7.0 Hz, 3H). 13C NMR
(101 MHz, CDCl3) δ 155.2 (C=O), 77.2, 69.5, 33.4, 26.4, 22.2,
13.7. IR (neat):  = 1786 cm-1 (C=O).

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Experimental
All substrates and reagents are commercially available and were
used as received. Carbon dioxide (purchased from PRAXAIR) was

used without further purification or drying prior to use. Procedures
for the synthesis of the PS supported catalyst systems can be found
in the Electronic Supplementary Information (ESI†). 1H and 13C
NMR spectra were recorded on a Bruker AV-400 or AV-500
spectrometer and referenced to the residual deuterated solvent
signals. IR spectra were obtained using a Bruker Alpha FT-IR.
Elemental analysis was performed by MEDAC Ltd, United
Kingdom.

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4-Methyl-1,3-dioxolan-2-one (5a).30 1H NMR (400 MHz,
CDCl3) δ 93 – 4.79 (m, 1H), 4.56 (dd, 2JHH = 8.5 and 3JHH = 7.6
Hz, 1H), 4.03 (dd, 2JHH = 8.5 and 3JHH = 7.2 Hz, 1H), 1.48 (d, 3JHH
= 6.3 Hz, 2H). 13C NMR (101 MHz, CDCl3) δ 155.1 (C=O), 73.6,
70.7, 19.4. IR (neat):  = 1781 cm-1 (C=O).
4-Chloro-1,3-dioxolan-2-one (6a).31 1H NMR (400 MHz,
CDCl3) δ 5.09 – 4.83 (m, 1H), 4.60 (dd, 2JHH = 8.5 and 3JHH = 8.5
Hz, 1H), 4.42 (dd, 2JHH = 8.5 and 3JHH = 5.8 Hz, 1H), 3.81 (dd, 2JHH
= 12.2 and 3JHH = 5.8 Hz, 1H), 3.75 (dd, 2JHH = 12.2 and 3JHH = 3.6
Hz, 1H). 13C NMR (101 MHz, CDCl3) δ 154.4 (C=O), 74.4, 67.0,
43.90. IR (neat):  = 1779 cm-1 (C=O).
4-(But-3-en-1-yl)-1,3-dioxolan-2-one (7a).32 1H NMR (500
MHz, CDCl3) δ 5.87 – 5.67 (m, 1H), 5.11 – 5.06 (m, 1H), 5.06 –
5.01 (m, 1H), 4.78 – 4.66 (m, 1H), 4.52 (dd, 2JHH = 8.6 and 3JHH =
8.6 Hz, 1H), 4.06 (dd, 2JHH = 8.6 and 3JHH = 7.2 Hz, 1H), 2.32 –
2.12 (m, 2H), 1.99 – 1.86 (m, 1H), 1.84 – 1.69 (m, 1H). 13C NMR
(126 MHz, CDCl3) δ 155.0 (C=O), 136.2, 116.3, 76.4, 69.4, 33.0,
28.6. IR (neat):  = 1783 cm-1 (C=O).

This journal is © The Royal Society of Chemistry 2013

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4-Phenyl-1,3-dioxolan-2-one (8a).30 1H NMR (400 MHz,
CDCl3) δ 7.52 – 7.40 (m, 3H), 7.40 – 7.32 (m, 2H), 5.69 (dd, 3JHH
= 8.5 and 8.0 Hz, 1H), 4.81 (dd, 2JHH = 8.5 and 3JHH = 8.5 Hz, 1H),
4.35 (dd, 2JHH = 8.5 and 3JHH = 8.0 Hz, 1H). 13C NMR (101 MHz,
CDCl3) δ 154.8 (C=O), 135.8, 129.7, 129.2, 125.9, 78.0, 71.2. IR
(neat):  = 1774 cm-1 (C=O).

† Electronic supplementary information (ESI†) available: Detailed
experimental procedures and details, copies of relevant NMR spectra of
known. See DOI: 10.1039/b000000x/.
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(9a).33

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15

1H

4,5-Dimethyl-1,3-dioxolan-2-one
trans-carbonate:
NMR (400 MHz, CDCl3) δ 4.39 – 4.27 (m, 2H), 1.44 (d, 3JHH = 5.9
Hz, 6H). 13C NMR (101 MHz, CDCl3) δ 154.33 (C=O), 79.9, 18.3.
IR Neat: 1774 cm-1 (C=O). cis-carbonate: 1H NMR (400 MHz,
CDCl3) δ 4.91 – 4.78 (m, 2H), 1.34 (d, 3JHH = 5.9 Hz, 6H). 13C
NMR (101 MHz, CDCl3) δ 154.3 (C=O), 76.1, 14.3. IR (neat):  =
1774 cm-1 (C=O).

70

2
3
4
5
6
7
8

75

9
10

80

11

(10a).34 1H

20

Hexahydrobenzo[d][1,3]dioxol-2-one
NMR (400
MHz, CDCl3) δ 4.71 – 4.66 (m, 2H), 1.94 – 1.82 (m, 4H), 1.66 –
1.55 (m, 2H), 1.46 – 1.37 (m, 2H). 13C NMR (101 MHz, CDCl3) δ
155.4 (C=O), 75.8, 26.7, 19.1. IR (neat): ν = 1784 cm-1 (C=O).

25

Tetrahydro-3aH-cyclopenta[d][1,3]dioxol-2-one (11a).35 1H
NMR (400 MHz, CDCl3) δ 5.12 – 5.08 (m, 2H), 2.15 – 2.06 (m,
2H), 1.83 – 1.61 (m, 4H). 13C NMR (101 MHz, CDCl3) δ 155.5
(C=O), 81.9, 33.1, 21.6. IR (neat): ν = 1780 cm-1 (C=O).

12

85

13
14
15

30

35

40

45

4-(phenoxymethyl)-1,3-dioxolan-2-one (12a).36 1H NMR (400
MHz, CDCl3) δ 7.37 – 7.29 (m, 2H), 7.07 – 7.02 (m, 1H), 6.96 –
6.91 (m, 2H), 5.08 – 5.01 (m, 1H), 4.63 (dd, 2JHH = 8.3, 3JHH = 8.3
Hz, 1H), 4.56 (dd, 2JHH = 8.3 Hz, 3JHH = 5.9 Hz, 1H), 4.25 (dd, 2JHH
= 10.6, 3JHH = 4.2 Hz, 1H), 4.17 (dd, 2JHH = 10.6 Hz, 3JHH = 3.6
Hz, 1H). 13C NMR (101 MHz, CDCl3) δ 157.8 (C=O), 129.7,
122.0, 114.6, 74.1, 66.9, 66.3. IR (neat): ν = 1784 cm-1 (C=O).
8,8a-dihydro-3aH-indeno[1,2-d][1,3]dioxol-2-one (13a).34 1H
NMR (400 MHz, CDCl3) δ 7.55 – 7.29 (m, 4H), 6.02 (d, 3JHH = 6.8
Hz, 1H), 5.49 – 5.43 (m, 1H), 3.43 – 3.39 (m, 2H). 13C NMR (101
MHz, CDCl3) δ 155.8 (C=O), 140.1, 136.5, 131.1, 128.3, 126.5,
125.7, 83.6, 79.8, 38.0. IR (neat): ν = 1786 cm-1 (C=O).

Acknowledgements
We would like to acknowledge financial support from the ICIQ
Foundation, ICREA and the Spanish Ministerio de Economía y
Competitividad (MINECO) through projects CTQ2011-27385
(AWK), CTQ2008-00947/BQU (MAP) and CTQ2012-38594C02-01 (MAP), DEC 2009SGR623 (MAP). C. A. thanks
MINECO for a Juan de la Cierva postdoctoral fellowship. A. H. H.
thanks the MECD for an FPU fellowship. We thank Dr. Alessandro
Ferrali for providing a sample of the indene oxide substrate.

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a

Institute of Chemical Research of Catalonia (ICIQ), Av. Països Catalans
16, 43007 – Tarragona (Spain). E-mail: mapericas@iciq.es;
akleij@iciq.es; Fax: +34 977920224; Tel: +34 977920247.
b
Catalan Institute for Research and Advanced Studies (ICREA), Pg. Lluís
Companys 23, 08010, Barcelona, Spain.
c
Departament de Química Orgànica, Universitat de Barcelona (UB),
08028 Barcelona, Spain.

This journal is © The Royal Society of Chemistry 2013

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Notes and references
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