作者:Robert J. Mycka、William T. Eckenhoff、Omar W. Steward、Nathan Z. Barefoot、Fraser F. Fleming
DOI:10.1016/j.tet.2012.10.016
日期:2013.1
allows highly diastereoselective alkylations controlled by the asymmetry of the remote carbinol stereocenter. Mechanistic experiments are consistent with γ-hydroxynitriles alkylating via a chelated magnesiated nitrile whereas δ-hydroxynitriles favor alkylation from acyclic magnesiated nitriles. Collectively these alkylations; are the first electrophile-dependent alkylations of acyclic nitriles, exhibit
用i - PrMgCl对γ-和δ-羟基腈进行去质子处理可实现高度非对映选择性的烷基化反应,该烷基化反应由远程甲醇立体中心的不对称性控制。机理实验与γ-羟基腈通过螯合的氧化镁腈烷基化是一致的,而δ-羟基腈则有利于无环氧化镁腈的烷基化。这些烷基化合在一起;是无环腈的首批依赖亲电试剂的烷基化反应,对用于去质子化的格利雅(Grignard)的性质表现出独特的影响,并解决了在构象可移动的无环腈中安装季铵盐中心的挑战。