Premium
Asymmetric Catalytic Formal 1,4‐Allylation of β,γ‐Unsaturated α‐Ketoesters: Allylboration/Oxy‐Cope Rearrangement
Author(s) -
Tang Qiong,
Fu Kai,
Ruan Peiran,
Dong Shunxi,
Su Zhishan,
Liu Xiaohua,
Feng Xiaoming
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201905533
Subject(s) - enantioselective synthesis , catalysis , chirality (physics) , chemistry , lewis acids and bases , substrate (aquarium) , conjugate , cope rearrangement , combinatorial chemistry , medicinal chemistry , stereochemistry , organic chemistry , chiral symmetry , physics , mathematics , mathematical analysis , oceanography , quantum mechanics , geology , nambu–jona lasinio model , quark
Abstract A highly enantioselective formal conjugate allyl addition of allylboronic acids to β,γ‐unsaturated α‐ketoesters has been realized by employing a chiral Ni II / N , N ′‐dioxide complex as the catalyst. This transformation proceeds by an allylboration/oxy‐Cope rearrangement sequence, providing a facile and rapid route to γ‐allyl‐α‐ketoesters with moderate to good yields (65–92 %) and excellent ee values (90–99 % ee ). The isolation of 1,2‐allylboration products provided insight into the mechanism of the subsequent oxy‐Cope rearrangement reaction: substrate‐induced chiral transfer and a chiral Lewis acid accelerated process. Based on the experimental investigations and DFT calculations, a rare boatlike transition‐state model is proposed as the origin of high chirality transfer during the oxy‐Cope rearrangement.