名称:
Cinchona based squaramide catalysed enantioselective Michael addition of α-nitrophosphonates to aryl acrylates: enantioselective synthesis of quaternary α-aminophosphonates
摘要:
Several cinchona based squaramide catalysts were applied to the asymmetric Michael addition of alpha-nitroethylphosphonates to acrylic acid aryl esters, resulting in high yields and enantioselectivities. The absolute configuration of one of the quaternary alpha-nitrophosphonate adducts was deduced from its experimental and calculated CD spectra. The adducts were reduced to their cyclic aminophosphonates by catalytic hydrogenation. (C) 2013 Elsevier Ltd. All rights reserved.
DOI:
10.1016/j.tetasy.2013.10.008