Stereo-selective synthesis of cis-alkenes/halo-alkenes by reaction of diphenylmethane with ethynylbenzenes via sp3 C–H bond activation promoted by iron salts

A stereo-selective reaction for the synthesis of cis-alkenes/halo-alkenes from diphenylmethane and ethynylbenzenes was developed in the presence of iron(III) bromide or chloride. Alkenyl bromides/chlorides were obtained in comparatively good yields in chlorobenzene under mild reaction conditions.