Copper complex of aminoisoborneol schiff base Cu 2(SBAIB-d) 2: An efficient catalyst for direct catalytic asymmetric nitroaldol (henry) reaction

Abstract

A new bifunctional copper complex of the aminoisoborneol Schiff base - Cu 2(SBAIB-d) 2 - has been developed for the effective direct catalytic asymmetric Henry reaction. One mol% of this catalyst produces the expected Henry products in high yields (up to 99%) with excellent enantioselectivities (up to 98% ee). The utility of the present catalyst was also extended to the Henry reaction with nitroethane and 1-nitropropane that furnished the corresponding products in moderate to high yields (up to 99%) with moderate to high enantioselectivities of syn (up to 98% ee) and anti (up to 98% ee) diastereomers. The highlights of this catalytic system are easy manipulation, air and moisture tolerance, the need for 1 mol% of an easily synthesizable catalyst and the high enantioselectivities achieved for a wide range of substrates. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.