C-3-Symmetrical Cinchonine-Squaramide as New Highly Efficient, and Recyclable Organocatalyst for Enantioselective Michael Addition

A novel and recyclable catalyst, a C-3-symmetrical cinchonine-squaramide, has been developed for the asymmetric Michael addition of 1,3-dicarbonyl compounds to nitroalkenes. When using only 1 mol% of catalyst 1a for the reaction, high reaction yields with excellent enantioselectivities and diastereo...

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Bibliographic Details
Published inAdvanced synthesis & catalysis Vol. 353; no. 14-15; pp. 2715 - 2720
Main Authors Min, Chang, Han, Xin, Liao, Zongquan, Wu, Xiangfei, Zhou, Hai-Bing, Dong, Chune
Format Journal Article
LanguageEnglish
Published WEINHEIM Wiley 01.10.2011
Subjects
Chemistry
Chemistry, Applied
Chemistry, Organic
Physical Sciences
Science & Technology
cinchonine-squaramide
1,3-DICARBONYL COMPOUNDS
QUATERNARY STEREOCENTERS
asymmetric Michael addition
ALKALOID DERIVATIVES
ALDEHYDES
SQUARIC ACID
catalyst recycling
KETONES
C-3-symmetrical species
ASYMMETRIC REDUCTION
THIOUREA CATALYSTS
BORANE REDUCTION
CONJUGATE ADDITION
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Summary:A novel and recyclable catalyst, a C-3-symmetrical cinchonine-squaramide, has been developed for the asymmetric Michael addition of 1,3-dicarbonyl compounds to nitroalkenes. When using only 1 mol% of catalyst 1a for the reaction, high reaction yields with excellent enantioselectivities and diastereoselectivities (up to 96% yield, >99% ee, >99:1 dr) were achieved, in which the results for cyclic keto esters are the best ever achieved. Moreover, 1a can be easily recovered by simple precipitation and was used for six cycles without losing any selectivity and activity.
ISSN:1615-4150
1615-4169
DOI:10.1002/adsc.201100066