Metal complexes of functionally sulfur ligands.: XIV.: Synthesis of thiosulfinato complexes via oxidative addition of platinum(0) complexes to 2,3,4-benzotrithiepin-1-oxide

The platinum(0) compounds L2Pt(eta(2)-C2H4) [L = PPh3, 1/2 dppf, 1/2 (R,R)-(-)-DIOP] 3a-c react with the 2,3,4-benzotrithiepin 1-oxides 2a-c to give the platinum(II) thiolato thiosulfinato complexes L2Pt[S-S(O)-CH2-(C6R2R22-CH2-S)-R-1] (R-1 = H, R-2 = CH3; R-1 = CH3, R-2 = H) 4a-6c. Treatment of 5a with an excess of PBu3 efficiently affords (Bu3P)(2)Pt[S-S(S)-CH2-C6Me2H2-CH2S] 7 by substitution of PPh3. Complex 7 reacts in solution with PBu3 to the platinum(II) sulfenato thiolato complex (Bu3P2),Pt[S(O)-CH2-C6Me2H2-CH2S] 8 as well as S = PBu3. The compounds 4a-6c have been characterized by analytical and spectroscopic methods. Simple qualitative MO calculations of the extended Huckel type by using the CACAO package indicate that the platinum(0) species acts as a Lewis acid attacking the nucleophilic sulfur atom S(3).