Lv Jian, Zhang Jiaming, Lin Zhu, Wang Yongmei
Department of Chemistry, Key Laboratory of Elemento-Organic Chemistry, Nankai University, 97 Weijin Road, Tianjin, China.
Chemistry. 2009;15(4):972-9. doi: 10.1002/chem.200801651.
A general enantioselective synthesis of functionalized nitrocyclopropanes by organocatalytic conjugate addition of a variety of bromonitroalkanes to alpha,beta-unsaturated enone systems is presented. The process, efficiently catalyzed by the salts of 9-amino-9-deoxyepiquinine 1 d serves as a powerful approach to the preparation of synthetically and biologically important cyclopropanes with high levels of enantio- and diastereoselectivities. Since only 0.6 equivalents of bromonitromethane are used as a reagent, (S)-2 e is obtained enantiomerically pure by employing chiral 1 d as a highly efficient catalyst for its kinetic resolution (97 % ee at 51 % conversion, selectivity s=120).
本文介绍了一种通过有机催化各种溴代硝基烷烃与α,β-不饱和烯酮体系进行共轭加成反应，对功能化硝基环丙烷进行通用对映选择性合成的方法。该过程由9-氨基-9-脱氧表奎宁1 d的盐高效催化，是一种制备具有高对映选择性和非对映选择性、在合成和生物学上都很重要的环丙烷的有效方法。由于仅使用0.6当量的溴代硝基甲烷作为试剂，通过使用手性1 d作为其动力学拆分的高效催化剂，可得到对映体纯的(S)-2 e（在51%转化率下ee为97%，选择性s = 120）。
