Novel thiophosphonodiamides as efficient hydrogen bond donor catalysts in tandem Michael addition–cyclization of malononitrile and 2-(E)-2-nitrovinylphenols
作者:Keling Hu、Youming Wang、Zhenghong Zhou、Chuchi Tang
DOI:10.1016/j.tet.2013.11.099
日期:2014.1
From L-amino acid, three chiral thiophosphonodiamides were prepared as new hydrogen bond donor organocatalysts. Under the mediation of the catalyst derived from L-valine, a tandem Michael addition/cyclization reaction between (E)-2-(2-nitrovinyl)phenols and malononitrile proceeds smoothly, giving pharmaceutically valuable 2-amino-4H-chromene-3-carbonitriles in high yields with 66-95% ee within 2 h. (C) 2013 Elsevier Ltd. All rights reserved.