UNPRECEDENTED REACTIVITY OF 1-ALKYNES WITH 2-CHLOROETHANOL PROMOTED BY CATIONIC SOLVENTO(TRIFLUOROMETHYL) PLATINUM(II) COMPLEXES - SYNTHESIS OF BETA-ALKOXYALKENYL DERIVATIVES AND X-RAY STRUCTURE OF =C(PH)OCH2CH2CL)(CO)(PPH3)(2)][BF4]CENTER-DOT-ET2O

Reactions at ambient temperature of the solvento cationic trifluoromet hyl complex trans[Pt(CF3)(PPh3)(2)(solv)] [BF4] with 1.5 equiv of 1-al kynes RC=CH (R = Ph, p-tolyl) and 2-chloroethanol afford in high yield the beta-alkoxyalkenyl complexes trans-[Pt(C(H)=C(R)-OCH2CH2Cl)(CO)(P Ph3)(2)][BF4] (R = Ph(1), p-tolyl (2)). In these reactions the CF3 gro up is also converted to a CO ligand. Complexes 1 and 2 were characteri zed by spectroscopic techniques and 1 also by an X-ray diffraction ana lysis. Reaction of the alkynyl complex trans-[Pt(CF3)(C=C-p-tolyl)(PPh 3)(2)] with 2-chloroethanol and 1 equiv of HBF4 gives the acetylide-ca rbonyl derivative trans-[Pt(C=C-p-tolyl)(CO)(PPh3)(2)][BF4] (3), which was also formed by reaction of trans-[Pt(CF3)(C=C-p-tolyl)(PPh3)(2)] with aqueous HBF4. Possible mechanisms of these reactions are discusse d.