N-heterocyclic carbene (ICyD) allowed both to catch the elusive monomeric (L)CuH and a cavity-controlled chemoselective copper-catalyzed hydrosilylation of α,β-unsaturated ketones. Remarkably, (α-ICyD)CuCl promoted the 1,2-addition exclusively, while (β-ICyD)CuCl produced the fully reduced product. The chemoselectivity is controlled by the size of the cavity and weak interactions between the substrate and internal
N杂环卡宾(ICyD)封端的
环糊精中的
铜包封既可以捕获难以捉摸的单体(L)CuH,也可以捕获由腔控制的
化学选择性
铜催化的α,β-不饱和酮的氢化
硅烷化。值得注意的是,(α-ICyD)CuCl专门促进了1,2-加成,而(β-ICyD)CuCl产生了完全还原的产物。
化学选择性由空腔的大小以及
环糊精的底物和内部CH键之间的弱相互作用控制。