Catalytic transformations of diazo compounds promoted by platinum(0) and dicationic platinum(II) complexes

9-Diazofluorene (DAF) is decomposed either stoichiometrically or catalytically in the presence of the platinum(0) complex [Pt(C2H4)(PPh3)2] to give difluoren-9-ylidene-hydrazine in high yield. Under analogous reaction conditions, diphenyldiazomethane gives mostly the azine, Ph2CNNCPh2, while ethyl diazoacetate (EDA) affords, in low yield, a mixture of diethyl fumarate and maleate in approximately 10:1 molar ratio. The cyclopropanation of styrene with EDA is catalyzed by a series of dicationic complexes of the type [PtL2(NCCH3)2][Y]2 (L2=2PPh3, Ph2PCH=CHPPh2, Ph2PCH2CH2PPh2; Y=BF4, CF3SO3) in 1,2-dichloroethane at 60 °C for 24 h. DAF and EDA undergo insertion reactions into the OH bond of alcohols ROH (R=Me, Et, t-Bu, CH2CHCH2, Ph) at 25 °C in CH2Cl2–ROH (DAF or EDA–ROH molar ratio 1/20) in the presence of 1% mol of several dicationic platinum(II) complexes to give the corresponding ethers in excellent yields.