Oxidative addition of alkyl halides to chiral cyclometallated platinum(II) complexes with thienyl imines. X-ray crystal structure of [PtMe{3-((S)-PhCHMeNCH)C4H2S}SMe2]

The reaction of [Pt2Me4(μ-SMe2)2] with ligand 3-((S)-PhCHMeNCH)C4H3S (1) produced the chiral cyclometallated compound [PtMe{3-((S)-PhCHMeNCH)C4H2S}SMe2] (2) which was characterized structurally. The reactions of 2 with phosphines gave compounds [PtMe{3-((S)-PhCHMeNCH)C4H2S}L] (L=PPh3 (3), P(2-MeC6H4)3 (4), Ph2PCH2CH2PPh2 (5)). The oxidative addition of methyl iodide to compounds 2 and 3 gave two diastereoisomers each of compounds [PtMe2I{3-((S)-PhCHMeNCH)C4H2S}L] (L=SMe2 (6a/6a′), PPh3 (7a/7a′)) in a ratio 2.1:1 and 2.4:1, respectively. Subsequent isomerization gave, in each case, a new pair of diastereoisomers. Compounds 4 and 5 failed to react with methyl iodide, while platinum(II) compounds [PtX{3-((S)-PhCHMeNCH)C4H2S}PPh3] (X=I (8), Br (9)) were obtained in the reactions of 3 with ethyl iodide or benzylbromide.