Premium
Controlling the α/γ‐Reactivity of Vinylogous Ketone Enolates in Organocatalytic Enantioselective Michael Reactions
Author(s) -
Iriarte Igor,
Olaizola Olatz,
Vera Silvia,
Gamboa Iñaki,
Oiarbide Mikel,
Palomo Claudio
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.201703764
Subject(s) - enantioselective synthesis , squaramide , stereocenter , bifunctional , michael reaction , chemistry , organocatalysis , ketone , reactivity (psychology) , diastereomer , tertiary amine , organic chemistry , addition reaction , catalysis , medicine , alternative medicine , pathology
Abstract The first regio‐, diastereo‐, and enantioselective direct Michael reaction of β,γ‐unsaturated ketones with nitroolefins is enabled by Brønsted base/hydrogen‐bonding bifunctional catalysis. A squaramide‐substituted tertiary amine catalyzes the reaction of a broad range of β,γ‐unsaturated ketones to proceed at the α‐site exclusively, giving rise to adducts with two consecutive tertiary carbon stereocenters in diastereomeric ratios of up to >20:1 and enantioselectivities generally in the 90–98 % ee range.