Solvent-free organocatalytic Michael addition of diethyl malonate to nitroalkenes: the practical synthesis of Pregabalin and γ-nitrobutyric acid derivatives
作者:Jin-ming Liu、Xin Wang、Ze-mei Ge、Qi Sun、Tie-ming Cheng、Run-tao Li
DOI:10.1016/j.tet.2010.11.053
日期:2011.1
enantioselective synthesis of Pregabalin 1 hydrochloride with good overall yield (44%) and enantioselectivity (98% ee) was described. The key step is an asymmetric Michael addition of equivalent of diethylmalonate and nitroalkene under solvent-free conditions using thiourea 2 as catalyst. The reaction can be applied to a variety of aromatic and aliphatic substituted nitroalkenes affording corresponding