Highly diastereoselective synthesis of (E)-1-trimethylsilyl-1-en-3-ynes, (1E, 3Z)- and (1E, 3E)-1-trimethylsilyl-1,3-dienes

Abstract In the stereospecific palladium-catalysed cross-coupling reaction of 1-alkynylzinc chlorides or (E)-1-alkenyl diisobutylalanes, (E)-2-bromovinyltrimethylsilane reacts preferentially, in the presence of the corresponding (Z) -stereoisomer to afford good yields of (E)-1-trimethylsilyl-1-en-3-ynes (4) or (1E, 3E)-1-trimethylsilyl -1,3-dienes ( 6 ), respectively, having very high stereoisomeric purities. Compounds 4 are easily converted into (1E, 3Z) -1-trimethylsilyl-1,3-dienes ( 5 ) by selective hydrometallation reactions, followed by protonolysis.