Sulfur(IV) compounds as ligands. part XXIV. Synthesis of halfsandwich ruthenium complexes of sulfinic acid esters

A series of halfsandwich ruthenium sulfinato complexes [CpRu(PR'(3))(2)(SO2 R)] (R = Me, CH2Ph, C2H4Ph, Ph, 4-C6H4Me; PR'(3) = PMe3, 1/2 dppm) with var ious electronic and steric environments around the ruthenium centre, have b een prepared by insertion of SO2 into a ruthenium carbon bond, by a direct ligand exchange reaction, or by oxidation of thiolato complexes with 3-chlo roperoxybenzoic acid. The chiral complexes [CpRu(CO)(PPh3)(SO2R)] (R = Me, CH2Ph, Ph) were obtained similarly by oxidation of the corresponding thiola tes with magnesium monoperoxyphthalate. Alkylation of the sulfinato complex es with oxonium salts [R"O-3]X (R" = Me, Et; X = BF4, PF6) gave ruthenium c omplexes of sulfinic acid esters, [CpRu(L)IL')(S(O)(OR")R)]X in high yields and, for the chiral complexes, up to 82% de. The esters may be detached fr om the metal by ligand exchange with acetonitrile. Stronger nucleophiles su ch as I- or SMe- dealkylate the coordinated sulfinic acid esters.