Hydromagnesiation of alkynylsilanes 1 gives (Z)-α-silylvinyl Grignard reagents 2, which are reacted with alkyl iodides or aryl iodides in the presence of CuI or Pd(PPh3)4 catalysts to afford (Z)-1,2-disubstituted vinylsilanes 3 in good yields. Intermediates 3 can undergo a desilylation reaction to give (E)-disubstituted alkenes 4 in high yields.
MoriK., The Total Synthesis of Natural Products, J. ApSimon, Ed., John Wiley, and Sons, Inc., New York, 1981, Vol. 4, PP 1-183.
2.
BartlettP.A., and JohnsonW.S., J. Am. Chem. Soc., 1973, 95, 7501; Van TamelenE.E., LeesR. G., and GriederA., J. Am. Chem. Soc., 1974, 96, 2255; ParkerK. A., and JohnsonW. S., J. Am. Chem. Soc., 1974, 96, 2556.
3.
HudrlikP.F., and PetersonD., J. Am. Chem. Soc., 1975, 97, 1464.
4.
ZweifelG., FisherR.P., SnowJ.T., and WhitneyC.C., J. Am. Chem. Soc., 1971, 93, 6309; BrownH.C., and BasavaiahD., J. Org. Chem., 1982, 47, 754; BrownH.C., LeeH.D., and KulkarniS.U., Synthesis, 1982, 195; BrownH.C., BasavaiahD., and KulkarniS.U., J. Org. Chem., 1982, 47, 3808.
5.
NegishiE., and Van HornD.E., J. Am. Chem. Soc., 1977, 99, 3168; NegishiE., OkukadoN., KingA.O., and SpiegelB.I., J. Am. Chem. Soc., 1978, 100, 2254.
6.
JanowiczH., and BergmanR.G., J. Am. Chem. Soc., 1983, 105, 3929.
7.
DenmarkS.E., and ChoiJ.Y., J. Am. Chem. Soc., 1999, 121, 5821.
