Conjugate Additions of a Simple Monosilylcopper Reagent with Use of the CuI·DMS Complex: Stereoselectivities and a Dramatic Impact by DMS
作者:Jesse Dambacher、Mikael Bergdahl
DOI:10.1021/jo048269e
日期:2005.1.1
reagent with DMS as the solvent is very useful with sterically hindered (β,β-disubstituted) enones, and provides very high yields of the β-silylated 1,4-addition products. Since there is no oligomerization problem associated with the simple monosilylcuprate reagent, this reagent should be considered as a very useful 1,4-silyl donor to enals, enones, and enoates in conjugate addition reactions.
描述了利用简单的单甲硅烷基铜酸盐试剂Li [PhMe 2 SiCuI]与α,β-不饱和羰基化合物进行共轭加成。作为(CuI)4(DMS)3配合物的组分或添加的溶剂,二甲基硫醚(DMS)的存在对其化学收率和非对映体比率(dr)的水平都具有惊人的影响。产品。吉尔曼型甲硅烷基氰基甲酸酯Li(Ph 2 MeSi)2 Cu / LiCN}先前已被用来保证在共轭加成反应中获得良好的结果。与简单的Li [PhMe 2]结合使用时,不需要外部添加剂,例如HMPA,三丁基膦或二烷基锌SiCuI]试剂。已经证明,以DMS为溶剂的单甲硅烷基铜酸盐试剂与空间受阻的(β,β-二取代的)烯酮非常有用,并且提供非常高产率的β-甲硅烷基化的1,4-加成产物。由于不存在与简单的单甲硅烷基铜酸酯试剂相关的低聚问题,因此该试剂应被认为是共轭加成反应中烯,烯酮和烯酸酯的非常有用的1,4-甲硅烷基供体。