Squaramide-catalyzed enantioselective Michael addition of malononitrile to chalcones
作者:Wen Yang、Yang Jia、Da-Ming Du
DOI:10.1039/c1ob06302b
日期:——
A highlyenantioselective Michael addition of malononitrile to chalconescatalyzed by a chiral quinine-derived squaramide catalyst has been developed. This organocatalytic reaction at a very lowcatalystloading (0.5 mol%) led to chiral γ-cyano carbonyl compounds in good yields with high enantioselectivities (up to 96% ee) under mild reaction conditions.
Chloramphenicol base chemistry. Part 11: 1 chloramphenicol base-derived thiourea-catalyzed enantioselective Michael addition of malononitrile to α , β -unsaturated ketones
The first chloramphenicol base-derived thiourea-catalyzed enantioselective Michael addition of malononitrile to alpha,beta-unsaturated ketones is reported. The Michael adducts were obtained in good to excellent yields (up to 98% yield) and enantioselectivities (up to 94% ee). This reaction has a broad substrate scope to various alpha,beta-unsaturated ketones. With this in mind, this methodology was successfully applied to the synthesis of a chiral piperidone, an advanced building block for dihydropyridinone P2X(7) receptor antagonists. (C) 2017 Published by Elsevier Ltd.