Alkyl Grignard reagents were found to be isomerized to more stable ones in high isomerization ratios (>99%) under cooperative catalysis by iron and copper, which promote isomerization of alkyl groups and transmetalation between Fe-Mg, respectively.
Iron-copper cooperative catalysis is shown to be effective for an alkene-Grignard exchange reaction and alkylmagnesiation of alkynes. The Grignard exchange between terminal alkenes (RCH═CH(2)) and cyclopentylmagnesium bromide was catalyzed by FeCl(3) (2.5 mol %) and CuBr (5 mol %) in combination with PBu(3) (10 mol %) to give RCH(2)CH(2)MgBr in high yields. 1-Alkyl Grignardreagents add to alkynes in the