Organocopper reagents in dimethylsulfide.

Organocopper(l) reagents, RCu, are both more stable and more reactive when prepared in dimethylsulfide instead of the more traditional solvents, ether and tetrahydrofuran. Furthermore, their preparation is both smoother and cleaner in dimethylsulfide. Excellent yields of products are observed with typical substrates such as alpha, beta-unsaturated ketones and acid chlorides. A wide range of Li reagents, including MeLi, nBuLi, tBuLi, PhLi, and allyllithium, have been investigated with good results, as have a selection of Grignard reagents, e.g., MeMgl, nBuMgBr, CyMgCl, and allylmagnesium bromide. Consequently, these RCu/Me sub 2 S reagents can be used in place of the less economical organocuprates, R sub 2 CuLi, in many applications.