Asymmetric Michael Addition of Malonates to Enones Catalyzed by a Primary β-Amino Acid and Its Lithium Salt
作者:Masanori Yoshida、Mao Narita、Shoji Hara
DOI:10.1021/jo201429w
日期:2011.10.21
Highly enantioselective Michaeladdition of malonates to enones was achieved using a mixed catalyst consisting of a primary β-amino acid, O-TBDPS (S)-β-homoserine, and its lithium salt. Various cyclic and acyclic enones were converted into 1,5-ketoesters in high yields (up to 92%) with high enantioselectivity (up to 97% ee) under mild reaction conditions. Details of synthesis of the catalyst, optimization
Highly enantioselective Michael addition of diethyl malonate to chalcones catalyzed by cinchona alkaloids-derivatived bifunctional tertiary amine-thioureas bearing multiple hydrogen-bonding donors
作者:Yulong Liu、Xie Wang、Xiaoyun Wang、Wei He
DOI:10.1039/c4ob00203b
日期:——
Chalcones are still challenge substrates in Michael reactions, and only limited success has been achieved. This work describes a highlyenantioselectiveMichaeladdition of diethyl malonate with chalcones catalyzed by cinchona alkaloids-derivatived bifunctional tertiary amine-thioureasbearingmultiplehydrogen-bondingdonors.
Enantioselective Michael addition of malonates to α,β-unsaturated ketones catalyzed by 1,2-diphenylethanediamine
作者:Wei Wang、Ling Ye、Zhichuan Shi、Zhigang Zhao、Xuefeng Li
DOI:10.1039/c8ra07809b
日期:——
A general and highly enantioselective Michaeladdition of malonates to cinnamones and chalcones has been developed. The commercially available 1,2-diphenylethanediamine could be directly utilized as the organocatalyst to furnish the desired adducts in satisfactory yield (61–99%) and moderate to excellent enantiopurity (65 to >99% ee). β-Ketoester was also a competent donor and was employed to construct
A General Organocatalytic Enantioselective Malonate Addition to α,β-Unsaturated Enones
作者:Veit Wascholowski、Kristian Rahbek Knudsen、Claire E. T. Mitchell、Steven V. Ley
DOI:10.1002/chem.200800673
日期:2008.7.7
A general enantioselective organocatalytic conjugate addition procedure of a variety of malonates to alpha,beta-unsaturated enone systems is presented. The reaction is efficiently catalysed by the pyrrolidinyl tetrazole catalyst 1. Cyclic, acyclic and aromatic enones can be used and the reaction with ethyl malonates 3 b provides the Michaeladdition products in high yields with good to excellent enantioselectivities