ALPHA-ADDITION OF AMINES, IMINES AND HYDR AZINES TO ALLENYLIDENE COMPLEXES - FORMATION OF CARBENE, ACETIDINYLIDENE AND NITRILE COMPLEXES

Diarylallenylidene(pentacarbonyl)-chromium and -tungsten complexes, (C O)5M=C=C=CR2 (M = W (1), Cr (2)), react with amines, imines and hydraz ines by addition of the nitrogen nucleophile to the C(alpha) allenylid ene atom. With NEt3 the adduct formation is reversible. With secondary and primary amines, imines and hydrazines, the initially formed N-yli de complexes react readily further to give carbene, azetidinylidene an d nitrile complexes, respectively. For example the reaction of (a) 1 a nd 2 with HNEt2 or H2NPh gives alkenyl(amino)carbene complexes, (CO)5M =C[C(H)=CR2] NR2 (3-5); (b) of 1 and 2 with HN=CR2 gives alkenyl(alkyl ideneamino)carbene complexes, (CO)5M=C[C(H)=CR2] [N=CR2'] (6,7); (c) o f 1 with ((i)Pr)N=C(Ph)H the azetidinylidene complex 9; (d) of 1 with 1,2-disubstituted hydrazines such as H(Me)NN(R)H (R = Me, Ph) alkenyl( hydrazino)carbene complexes, (CO)5W=C[C(H)=CR2] [N(Me)N(R)H] (11) and (e) of 1 with H2NNR1R2 (R1 = R2 = H, Me; R1 = H, R1 = Ph) alkenyl(amin o)carbene complexes (13) and/or acrylnitrile complexes, (CO)5W[N = C-C (H)=CR2](12). The structures of representative examples of 6, 11 and 1 2 were established by X-ray analyses.