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Use of a (β‐Amidoallyl)boronate as a Nucleophilic Reagent in Catalytic Enantioselective Addition to Isatins
Author(s) -
Sengoku Tetsuya,
Sugiyama Akihiro,
Kamiya Yuta,
Maegawa Ryunosuke,
Takahashi Masaki,
Yoda Hidemi
Publication year - 2017
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201601612
Subject(s) - enantioselective synthesis , chemistry , diethylzinc , oxindole , catalysis , nucleophile , organic chemistry , combinatorial chemistry , enantiopure drug , reagent , pyrazolones , amide
Spirocycles are attractive synthetic targets for many synthetic chemists owing to their potent and promising biological activities. We previously reported a method for the highly enantioselective allylation of various isatins with β‐amido‐functionalized allylstannanes under the influence of indium‐based chiral catalysts and applied this method to the synthesis of 2‐oxindole derivatives spiro‐fused to an α‐methylene‐γ‐butyrolactone framework. In this communication, we report the successful development of a new catalytic system that enables enantioselective tin‐free “amide allylation” with the aid of a newly prepared (β‐amidoallyl)boronate for nucleophilic addition to isatins. This system consisting of a catalytic amount of diethylzinc as a competitive candidate in the presence of chiral 1,3‐amino alcohols incorporating an acidic phenol functionality offers new opportunities for environmentally benign access to medicinally relevant spirocyclic 2‐oxindoles.