An Asymmetric Michael Addition of α,α-Disubstituted Aldehydes to Maleimides Leading to a One-Pot Enantioselective Synthesis of Lactones Catalyzed by Amino Acids
作者:Christoforos G. Kokotos
DOI:10.1021/ol4008662
日期:2013.5.17
A cheap and fast construction of both enantiomers of substituted succinimides is reported. α- or β-amino acids, such as β-phenylalanine and α-tert-butyl aspartate, were found to be efficient organocatalysts for the reaction between α,α-disubstituted aldehydes and maleimides. Products containing contiguous quaternary-tertiary stereogenic centers are obtained in high to quantitative yields and excellent
Organocatalytic enantioselective conjugate addition of aldehydes to maleimides in deep eutectic solvents
作者:Jesús Flores-Ferrándiz、Rafael Chinchilla
DOI:10.1016/j.tetasy.2016.12.009
日期:2017.2
The conjugate enantioselective addition of aldehydes, mainly alpha,alpha-disubstituted, to maleimides leading to enantioenriched succinimides, has been achieved in recyclable deep eutectic solvents at room temperature. Enantiomerically pure carbamate-monoprotected trans-cyclohexane-1,2-diamines are used as organocatalysts, affording high yields and up to 94% ee of the final succinimides. The product can be extracted from the deep eutectic solvent, which retains the chiral organocatalyst, allowing both the solvent and catalyst to be reused. (C) 2016 Elsevier Ltd. All rights reserved.