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Asymmetric Catalytic Vinylogous Addition Reactions Initiated by Meinwald Rearrangement of Vinyl Epoxides
Author(s) -
Xu Jinxiu,
Song Yanji,
He Jun,
Dong Shunxi,
Lin Lili,
Feng Xiaoming
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202102054
Subject(s) - catalysis , chemistry , enantioselective synthesis , lewis acids and bases , catalytic cycle , stereoselectivity , cyclohexene , transition state , organic chemistry , epoxide , reaction mechanism , combinatorial chemistry
The first catalytic asymmetric multiple vinylogous addition reactions initiated by Meinwald rearrangement of vinyl epoxides were realized by employing chiral N , N ′‐dioxide/Sc III complex catalysts. The vinyl epoxides, as masked β,γ‐unsaturated aldehydes, via direct vinylogous additions with isatins, 2‐alkenoylpyridines or methyleneindolinones, provided a facile and efficient way for the synthesis of chiral 3‐hydroxy‐3‐substituted oxindoles, α,β‐unsaturated aldehydes and spiro‐cyclohexene indolinones, respectively with high efficiency and stereoselectivity. The control experiments and kinetic studies revealed that the Lewis acid acted as dual‐tasking catalyst, controlling the initial rearrangement to match subsequent enantioselective vinylogous addition reactions. A catalytic cycle with a possible transition model was proposed to illustrate the reaction mechanism.