An efficient bismuth(III) chloride-catalyzed synthesis of 1,1-diarylalkenes via Friedel-Crafts reaction of acyl chloride or vinyl chloride with arenes

In the presence of catalytic amount of bismuth(III) chloride, the reactions of acyl chlorides or vinyl chlorides with arenes afforded 1,1-diarylatkenes in 25-82% isolated yield. In the case of the reaction of acyl chlorides with arenes, the procedure includes an initial Friedel-Crafts acylation, subsequent formation of vinyl chlorides and final Friedel-Crafts-type vinylation of another arene molecule with vinyl chloride. This paper reports the first Lewis acid-catalyzed cleavage of the C-Cl bond of vinyl chloride and its application in the synthesis of multiply subtituted alkenes.