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Phosphine‐mediated Highly Enantioselective Spirocyclization with Ketimines as Substrates
Author(s) -
Han Xiaoyu,
Chan WaiLun,
Yao Weijun,
Wang Yongjiang,
Lu Yixin
Publication year - 2016
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201600453
Subject(s) - enantioselective synthesis , stereocenter , phosphine , isatin , annulation , cycloaddition , chemistry , reactivity (psychology) , combinatorial chemistry , organocatalysis , catalysis , organic chemistry , stereochemistry , medicine , alternative medicine , pathology
Abstract Phosphine‐catalyzed enantioselective annulation reactions involving ketimines are a daunting synthetic challenge owing to the intrinsic low reactivity of ketimine substrates. A highly enantioselective [3+2] cycloaddition reaction that makes use of isatin‐derived ketimines as reaction partners was developed. Notably, both simple and γ‐substituted allenoates could be utilized, and various 3,2′‐pyrrolidinyl spirooxindoles with a tetrasubstituted stereocenter were obtained in excellent yields and with nearly perfect enantioselectivity (>98 % ee in all cases).