Synthesis and cyclization reactions of platinum(Il)-coordinated arsonium-substituted phenyl isocyanides, o-(I-R3As+-CH2)C6H4N C

The arsonium-substituted isocyanides, o-(I-R3As+CH2)C6H4NC (AsR3 = AsPh3, L-1; AsMePh2, L-2; AsMe2Ph, L-3), were prepared by reaction of o-(chloromethyl)phenyl isocyanide, o-(CH2Cl)C6H4NC, with a slight molar stoichiometric amount of the arsine in the presence of a Mold excess of NaI in acetone at room temperature. The isocyanides L-1-L-3 coordinate to some Pt(II) complexes such as trans-[PtX{o-(I-R3As+CH2)C6H4NC}(PPh3)2] [BF4] (AsR3 = AsPh3, 1; AsMePh2, 2; AsMe2Ph, 3; X = Cl, I) and [PtX {o-(I-R3As+CH2)C6H4NC}(Ph2PCH=CHPPh2)] [BF4] (AsR3 = AsMePh2, 4; X = Cl, I). Complexes 2-4 are converted in CH2Cl2 at room temperature in the presence of NEt3 to the corresponding indolidin-2-ylidene derivatives trans-[PtX{CN(H)-o-C6H4C(AsR3)}(PPh3)2]BF4] (AsR3 =AsPh3, 5; AsMePh2, 6; AsMe2Ph, 7) and [PtX{CN(H)-o-C6H4(AsMePh2)}(Ph2PCH=CHPPh2)][BF4] (8). (C) 2004 Elsevier B.V. All rights reserved