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Nickel‐Catalyzed Conjugate Addition of Silyl Ketene Imines to In Situ Generated Indol‐2‐ones: Highly Enantioselective Construction of Vicinal All‐Carbon Quaternary Stereocenters
Author(s) -
Zheng Jianfeng,
Lin Lili,
Dai Li,
Tang Qiong,
Liu Xiaohua,
Feng Xiaoming
Publication year - 2017
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201705943
Subject(s) - vicinal , stereocenter , ketene , enantioselective synthesis , conjugate , nickel , silylation , catalysis , in situ , carbon fibers , chemistry , organic chemistry , materials science , mathematics , mathematical analysis , composite number , composite material
The first enantioselective conjugate addition of silyl ketene imines to in situ generated indol‐2‐ones was performed in the presence of a chiral N , N ′‐dioxide/Ni II catalyst. This method provides efficient access to chiral β‐alkyl nitriles bearing congested vicinal all‐carbon quaternary stereocenters in up to 90 % yield with 23:1 d.r. and 98 % ee . The products enable facile transformations to chiral pyrroloindoline frameworks and spirocyclohexane oxindole derivatives. A possible transition state was also proposed to explain the origin of the asymmetric induction.