Enantioselective synthesis of 2-amino-5,6,7,8-tetrahydro-5-oxo-4H-chromene-3-carbonitriles using squaramide as the catalyst
作者:Yu Gao、Da-Ming Du
DOI:10.1016/j.tetasy.2012.09.011
日期:2012.10
The organocatalyzed enantioselective synthesis of a series of chiral 2-amino-5,6,7,8-tetrahydro-5-oxo-4H-chromene-3-carbonitriles was achieved using bifunctional squaramides as the catalysts. The tandem Michael addition-cyclization reaction of cyclohexane-1,3-diones and benzylidenemalononitriles gave the corresponding products in excellent yields (up to 99%) and moderate to good enantioselectivities (up to 83% ee). This investigation provides an efficient and useful process for the synthesis of chiral 2-amino-4H-chromenes. (C) 2012 Elsevier Ltd. All rights reserved.
Organocatalytic Asymmetric Michael Addition of 1,3-Cyclohexanedione to Benzylidenemalonitriles
作者:Chang Won Suh、Dae Young Kim
DOI:10.5012/bkcs.2014.35.1.98
日期:2014.1.20
The organocatalytic enantioselective Michael addition reaction promoted by chiral binaphthyl-modified squaramide catalyst have been developed, allowing facile synthesis of the corresponding chiral 2-amino-4H-chromenes derivatives with excellent enantioselectivity (up to 99% ee). The method reported represents a practical entry for the preparation of chiral 2-amino-4H-chromenes derivatives.