Título:
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Asymmetric [4+2] Annulation Reactions Catalyzed by a Robust, Immobilized Isothiourea
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Autor/a:
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Wang, Shoulei; Izquierdo, Javier; Rodríguez-Escrich, Carles; Pericàs, Miquel A.
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Abstract:
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A polystyrene-supported isothiourea (1a) behaves as a highly efficient organocatalyst in a variety of formal [4 + 2] cycloaddition reactions. The catalytic system has proven to be highly versatile, leading to six-membered heterocycles and spiro-heterocycles bearing an oxindole moiety in high yields and very high enantioselectivities (32 examples, including the previously unreported oxindole spiropyranopyrazolones 8; 97% mean ee). The notable chemical stability of 1a under operation conditions results in high recyclability (11 cycles, accumulated TON of 76.8) and allows the implementation of an extended-operation continuous flow process (no decrease in yield or ee after 18 h). |
Fecha de creación:
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13-03-2017 |
Materia(s):
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Quimica |
Derechos:
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L'accés als continguts d'aquest document queda condicionat a l'acceptació de les condicions d'ús establertes per la següent llicència Creative Commons: http://creativecommons.org/licenses/by-nc-nd/4.0/ |
Páginas:
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2780 p. |
Tipo de documento:
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Artículo Artículo - Borrador |
DOI:
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10.1021/acscatal.7b00360
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Editor:
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ACS Catal.
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Compartir:
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