REGIOSELECTIVE AND STEREOSELECTIVE ALLYLIC COUPLING REACTIONS OF ALLYLTRIFLUOROSILANES

Regio- and stereoselective cross-coupling reactions using altyltrifluorosilanes are reviewed. gamma-Selective allylation of organic halides or triflates with allyltrifluorosilanes takes place in the presence of a fluoride salt and Pd(PPh(3))(4) as a catalyst, giving the corresponding allylic compounds in good yields. The regioselectivity of this reaction is strongly influenced by a palladium catalyst;high alpha-selectivity was observed in reactions catalyzed by PdCl2[Ph(2)P(CH2)(n)PPh(2)] (n = 2 or 3). Optically active allylsilanes undergo the gamma-selective allylation of aryl triflates to give optically active allylic arenes. The absolute configuration of the allylic arenes could be controlled by choosing a fluoride salt. Allylation of quinones with allyltrifluorosilanes takes place with high regioselectivity in the presence of FeCl3 . 6 H2O. This method was used to synthesize biologically active isoprenoid quinones such as plastoquinone-1 and vitamin K-1.