Synthesis, structure, and reactivity of rhenium N-isocyanide complexes ReBr(CO)(3)(CNR)(CNNPPh3)

The rhenium isocyanide complex ReBr(CO)(3)(CNR)(NCMe) (1) reacted with CNNP Ph3 in CH2Cl2 to give ReBr(Co)(3)(CNR)(CNNPPh3) (2a, R = Ph; 2b, R = Pr) in good yields. Treatment of 2 with ketones in the presence of a catalytic am ount of HBF, yielded the derivatives ReBr(CO)(3)(CNR)(CNN=CR'R ") (3). The complex ReBr(CO)(3)(CNR)(CNN=CMe2) on reaction with isopropylamine gave the amino(hydrazono)carbene complex ReBr(CO)(3)(CNR) {C(NHPri)(NHN=CMe2)} (4). Prolonging the reaction of 3a (R=Ph, R'=R "=Me) with isopropylamine in CDC l3, it was converted first into ReBr(CO)(3)(CNPh) {C(NHPri)(NHN=CMe2)}, fol lowed by the formation of the biscarbene product ReBr(CO)(3){C(NHPri)(NHPh) } {C(NHPri)(NHN=CMe2)} (5). The complexes ReBr(CO)(3)(CNPr)(CNNPPh3) (2b) a nd ReBr(CO)(3)(CNPh)(CNN=CMe2) (3a) have been characterized by single-cryst al X-ray diffraction analyses. (C) 1999 Elsevier Science S.A. All rights re served.