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 Grignard reagents. It is confirmed that oxidative addition of alkyl halide to cobalt
proceeds via a radical process. Optically pure Ueno-Stork halo acetals undergo diastereoselective cross-coupling reactions, the products of which are transformed into optically active THF derivatives. A sequential
radical cyclization/arylation reaction under cobalt catalysis provides extremely short access to a synthetic
prostaglandin AH13205.