Luzung Michael R, Toste F Dean
Center for New Directions in Organic Synthesis, Department of Chemistry, University of California, Berkeley, California 94720, USA.
J Am Chem Soc. 2003 Dec 24;125(51):15760-1. doi: 10.1021/ja039124c.
A mild method for the regioselective coupling of propargyl alcohols and allylsilanes is described. The method employs an air- and moisture-tolerant rhenium-oxo complex ((dppm)ReOCl3) as a catalyst for the formation of sp3-carbon-sp3-carbon bonds without the need for prior activation of the propargyl alcohol as a halide or pseudohalide. The stability of the high oxidation state rhenium complex allows for simple reisolation and reuse of the catalyst. A broad range of functional groups is tolerated including aryl halides, olefins, esters, and acid-labile functional groups such as acetals. Furthermore, displacement of the alcohol occurs preferentially even in the presence of other electrophiles such as primary alkyl halides and conjugated esters. The use of enantiopure crotylsilanes as coupling partners allows for the asymmetric construction of two adjacent stereocenters. The potential of this reaction is demonstrated in an asymmetric synthesis of delta-lactone, di-O-methylcalopin.
本文描述了一种用于炔丙醇和烯丙基硅烷区域选择性偶联的温和方法。该方法采用一种耐空气和湿气的铼氧配合物（(dppm)ReOCl3）作为催化剂，用于形成sp3-碳-sp3-碳键，而无需将炔丙醇预先活化成卤化物或拟卤化物。高氧化态铼配合物的稳定性使得催化剂能够简单地重新分离和再利用。该反应能耐受多种官能团，包括芳基卤化物、烯烃、酯以及对酸不稳定的官能团（如缩醛）。此外，即使存在其他亲电试剂（如伯烷基卤化物和共轭酯），醇的取代反应也优先发生。使用对映体纯的巴豆基硅烷作为偶联伙伴，可以不对称构建两个相邻的立体中心。该反应的潜力在δ-内酯二-O-甲基卡洛芬的不对称合成中得到了证明。
