Effective construction of quaternary stereocenters by highly enantioselective α-amination of branched aldehydes
作者:Ji-Ya Fu、Xiao-Ying Xu、Yan-Chun Li、Qing-Chun Huang、Li-Xin Wang
DOI:10.1039/c0ob00406e
日期:——
A highly efficient enantioselectiveα-amination of branchedaldehydes with azadicarboxylates promoted by chiral proline-derived amide thiourea bifunctional catalysts was developed for the first time, affording the adducts bearing quaternary stereogenic centers with excellent yields (up to 99%) and enantioselectivities (up to 97% ee).
A series of secondaryamine-thioureacatalysts 1a-1d derived from L-proline and chiral diamine were prepared and successfully applied to the Michael addition of acetone to trans-nitroalkenes in excellent yields (up to 99%) and enantioselectivities (44-91% ee).
A series of secondary amine–thiourea catalysts derived from l-proline and chiral diamine were prepared and successfully applied to the highly effective and enantioselectiveα-amination of unmodified aldehydes with various azodicarboxylates in excellent yields (up to 99%) and enantioselectivities (up to 99% ee) within a few minutes.