Highly chemo- and stereoselective palladium-catalyzed transfer semihydrogenation of internal alkynes affording cis -alkenes

摘要

DMF (N,N-dimethylformamide)/KOH was found to be an efficient hydrogen source in the Pd(OAc)_2-catalyzed transfer semihydrogenation of various functionalized internal alkynes to afford cis-alkenes in good to high yields with excellent chemo- and stereoselectivity. This catalytic process was also applied to the synthesis of analogues of combretastatin A-4.