First Coordinatively Saturated carbene complexes of platinum(II): Synthesis, structure, and reactivity

Coordinatively saturated carbene complexes of platinum(II) have been obtained by oxidative addition of [ClCH=NMe2]Cl to Pt(0) precursors. The cationic products of general formula [PtCl(CHNMe2)(N,N-chelate)(olefin)]Cl have been characterized through NMR spectroscopy and for [PtCl(CHNMe2)(2,9-Me-2-1,10-phen)(Z-MeO2CCH=CHCO2Me)]Cl by X-ray diffractometry. The latter species reacts with nucleophiles affording dimethylformamide and the corresponding Pt(0) precursor [Pt(2,9-Me-2-1,10-phen)(Z-MeO2CCH=CHCO2Me)]. Attempts to obtain related complexes containing carbene groups Pt=CHY without a heteroatom in alpha-position (Y = CO2Et, CO2NMe2, CN) have led to the isolation of complexes of formula [PtR(dmphen){eta(1),eta(2)-CH(Y)O2CCH=CHCO2Me}] (R = Me, Ph), Formally derived fi om an intrasnolecular nucleophilic addition to a carbene intermediate. The X-ray structure of a representative product, [PtMe(dmphen){eta(1),eta(2)-CH(CO2Et)O2CCH=CHCO2Me}], is reported.