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) (L-2 = 2PPh(3), Ph2PCH = CHPPh2, Ph2PCH2CH2PPh2: Y = BF4. CF3SO3) in 1,2-dichloroethane at 60 degreesC 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 degreesC 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. (C) 2002 Elsevier Science B.V. All rights reserved.