ORGANIC SYNTHESES VIA TRANSITION-METAL COMPLEXES .78. HYDRAZINOLYSIS OF ALKYNYLCARBENE COMPLEXES OF CHROMIUM AND TUNGSTEN - FORMATION OF HYDRAZINOCARBENE, IMIDATE, PYRAZOLIDINYLIDENE, AND NITRILE COMPLEXES

Hydrazinolysis of alkynylcarbene complexes (CO)(5)M=C(OEt)C=Ph (1, M = W; 1', M = Cr) with mono- and 1,2-dimethylhydrazine MeHNNHR (2a,b) (R = Me, H) affords three different-type compounds: hydrazinocarbene complexes (CO)(5)M=C(NMe-NHR)C=CPh [(E/Z)-3a,b], imidate complexes (CO)(5)M[MeN=C(OEt)-C=CPh] [(E/Z)-4a], and pyrazolidinylidene complexes 5a,b. Hydrazinolysis of 1/1' with 1,l-dimethylhydrazine or (unsubstituted) hydrazine H(2)NNR(2) (2c,d) (R = Me, H) yields hydrazinocarbene complexes (CO)(5)M=C(NHNR(2))C=CPh [(E/Z)-3c], imidate complexes (CO)(5)M[HN=C(OEt)C=CPh] [(E/Z)-4a], and benzonitrile complexes (CO)(5)M(N=CPh)(8). Hydrazinolysis of 1 with H(2)NNHR (2e,f) (R = COMe, Ph) gives pyrazoles 12e,f as the only products. The product composition of the reactions of 2a-d with 1 is markedly influenced by the reaction temperature. Reaction of 1 with N- and O-methylhydroxylamines (13, 14) affords imidate complexes 4 only. The hydrazinocarbene complexes (E)-3a and (Z)-3c were characterized by X-ray diffraction. Both compounds crystallize in space group P $($) over bar$$ 1 (No. 2): (E)-3a, C16H12N2O5W, cell parameters a = 8.501(2) Angstrom, b = 9.645(2) Angstrom, c = 11.860(2) Angstrom, alpha = 103.56(2)degrees, beta = 95.59(2)degrees; gamma = 111.76(2)degrees, Z = 2, R(1) = 0.043, and wR(2) = 0.083; (Z)-3c, C16H12N2O5W, cell parameters a = 9.380(3) Angstrom, b = 9.685(4) Angstrom, c = 10.804(3) Angstrom, alpha = 84.77(5)degrees, beta = 80.74(3)degrees, gamma = 66.47(3)degrees, Z = 2, R(1) = 0.036, and wR(2) = 0.086.