Manganese(I) and rhenium(I) tricarbonyl (Alkylthio)methyl and alkylidenesulfonium complexes

The reactions of Na[M(CO)(3)(bipy)] (M = Mn, Re) compounds with ClCH2SR (R = Me, Ph) afford the (alkylthio)alkyl complexes [Mn(CH2SMe)(CO)(3)(bipy)] (1a), [Mn(CH2SPh)(CO)(3)-(bipy)] (1b), [Re(CH2SMe)(CO)(3)(bipy)] (2a), and [Re(CH2SMe)(CO)(3)(bipy)] (2b). Methylation at sulfur of these compounds with methyl triflate affords the methylidenesulfonium cations [Mn(CH2SMe2)(CO)(3)(bipy)](+) (5a), [Mn(CH2SMePh)(CO)(3)(bipy)](+) (5b), [Re(CH2SMe2)(CO)(3)(bipy)](+) (6a), and [Re(CH2SMePh)(CO)(3)(bipy)](+) (6b) as their triflate salts. These new compounds were characterized by IR and NMR spectroscopy, and the crystal structures of 1b, 2a, 5b, and 6b have been determined by X-ray diffraction. The sulfonium complexes are unreactive toward PPh3 and pyridine. The reactions of 5b and 6b with I-, PPh2-, and SEt(-)anions afford the (phenylthio)methyl complexes 1b and 2b, resulting from nucleophilic attack at the methyl group. 5b and 6b react with styrene to give phenylcyclopropane, free thioanisole, and the corresponding [M(OTf)(CO)(3)(bipy)] complex.