Cu-catalyzed alkylation of Grignard reagents: A new efficient procedure

The presence of NMP (4-9 equiv.) clearly improves the yield and the chemose lectivity of the Cu-catalyzed alkylation of organomagnesium reagents. Thus, secondary and tertiary alkylmagnesium chlorides were used successfully for the first time in such a reaction and ester, amide, nitrile or keto groups are tolerated. The procedure is cheap, environmentally friendly and very e asy to carry out (1-3% Li2CuCl4 or CuCl, THF, 20 degrees C). It is an inter esting alternative to the classical alkylation of organocuprates reagents. (C) 2000 Published by Elsevier Science Ltd.