Disclosed is a process of carrying out a Michael reaction with recovery of the catalyst, where a compound of formula (1):
is reacted with a compound of formula (2):
in the presence of a catalyst of formula (4):
where the compounds of formulae (1) and (2) undergo a Michael reaction.
Highly enantioselective Michael addition of 1,3-dicarbonyl compounds to nitroalkenes catalyzed by designer chiral BINOL–quinine–squaramide: efficient access to optically active nitro-alkanes and their isoxazole derivatives
A chiral BINOL-quinine-squaramide has been identified as the best catalyst for the asymmetric Michael addition of nitroalkenes to 1,3-dicarbonyl compounds. A series of chiral nitroalkanes were prepared with approximately >99% ee. Furthermore, the methodology was applied successfully to the synthesis of enantiomerically pure isoxazoles derivatives (>99% ee). (C) 2013 Elsevier Ltd. All rights reserved.
US8940938B2
申请人:——
公开号:US8940938B2
公开(公告)日:2015-01-27
Recyclable organocatalysis: highly enantioselective Michael addition of<b>1,3-diaryl-1,3-propanedione</b>to nitroolefins
作者:Bin Tan、Xuan Zhang、Pei Juan Chua、Guofu Zhong
DOI:10.1039/b813915f
日期:——
The first Michael addition of 1,3-diaryl-1,3-propanedione to nitroolefins was demonstrated using a simple organocatalyst, which afforded excellent yields (81–97%) and enantioselectivities (90 to >99% ee); the catalyst and excess reactant can be reused seven times through a simple filtration operation.