Ru(ii)-catalyzed cascade cis carbohalogenation and cyclization of alkyne-tethered cyclohexadienones for synthesizing tetrasubstituted alkenes

We have established an efficient ruthenium(ii)-catalyzed cis carbohalogenation and carbooxygenation cyclization of internal alkyne-tethered cyclohexadienones with halide and acetate ions, which produces a series of alkenyl halides and acetates with hydrobenzofuran skeletons in high yields and features high atom economy and regio- and stereoselectivity. Furthermore, the obtained hydrobenzofuran products can easily undergo aromatization and subsequent cross-coupling reactions, which provide a novel and stereoselective approach to synthesize tetrasubstituted alkenes, particularly diarylalkenes and triarylalkenes.