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