PALLADIUM-CATALYZED DIASTEREOSELECTIVE SYNTHESES OF (E)-1-TRIMETHYLSILYL-2-ALKENES, (E)-1-TRIMETHYLSILYL-1-ALKEN-3-YNES, (1E,5E)-1-TRIMETHYLSILYL-1,5-ALKADIEN-3-YNES, (1E,3Z)- AND (1E,3E)-1-TRIMETHYLSILYL-1,3-ALKADIENES

Article abstract of DOI:10.1016/S0040-4020(01)89506-5

On the basis of our observation that (E)-1-bromo-1-alkenes undergo preferentially stereospecific Pd-catalyzed cross-couplings with a variety of organometallics, in the presence of the corresponding (Z)-stereoisomers, efficient and convenient diastereoselective procedures have been developed to prepare nearly stereoisomerically pure (E)-1-trimethylsilyl-2-alkenes (4), (E)-1-trimethylsilyl-1-alken-3-ynes (5), (1E,5E)-1-trimethylsilyl-1,5-alkadien-3-ynes (6), and (1E,3E)-1-trimethylsilyl-1,3-alkadienes (8) from stereoisomeric mixtures of alkenyl bromides.Compounds 5 have been stereoselectively converted into (1E,3Z)-1-trimethylsilyl-1,3-dienes (7) by selective hydrometallations, followed by hydrolysis.Some synthetic applications of compounds 5-8 have been also examined.