Novel (Trimethylgermyl)copper(I) Reagents: Preparation and Addition to α,β-Unsaturated Ketones and α,β-Alkynic Esters

The preparation of the novel (trimethylgermyl)cuprates (Me 3 Ge) 2 CuLi ( 2 ), Me 3 GeCu(CN)Li ( 3 ), (Me 3 Ge) 2 Cu(CN)Li 2 ( 4 ), and Me 3 Ge(Me)Cu(CN)Li 2 ( 5 ) is described. (Trimethylgermyl)copper(I) reagents add, in a 1,4-fashion, to α,β-unsaturated ketones and α,β-alkynic esters.