Cobalt(diamine)-catalyzed cross-coupling reaction of alkyl halides with arylmagnesium reagents: Stereoselective constructions of arylated asymmetric carbons and application to total synthesis of AH13205

A cobalt-diamine complex catalyzes the cross-coupling reactions of primary and secondary alkyl halides with aryl Gringard reagents and the oxidative addition of alkyl halide to cobalt proceeds by a radical process. High stereoselectivity is observed in the sequential cyclation/ arylation reaction, leading to the short total synthesis of the synthetic prostaglandin AH13205.