Isocyanide complexes hydrazine

Complex 61 is also accessible from the 2-nitrophenyl isocyanide complex 68 by reduction of the nitro group with Sn/HCl. Incomplete reduction of the nitro group in 68 with Raney-Nickel/hydrazine yields, after intramolecular cyclization, the complex 70 with the NH,NOH-stabilized benzimidazolin-2-ylidene ligand. Complex 69 with the 2-hydoxylamin-substituted phenyl isocyanide ligand presumably occurs as an intermediate in this reaction. The alkylation of both the NH,NH- and the NH, NOH-stabilized NHC ligands in 67 and 70, respectively, proceeds readily (Fig. 23) [184, 185]. 

Organogold carbene compounds [Au(carbene)(CN) j iR ] can be obtained from com-plexed cyanides [Au(CN)m(C6F5) ] (n = 1 or 3, m = 1 and n = m = 2) by sequential alkylation (to form isocyanide complexes) and nucleophilic attack of amine" . Gold(III) diisocyanides [Au(CNR)2(CgF5)2]+ (R = Ph or p-tolyl), which can also be obtained by isocyanide substitution of ether in [Au(C6F5)2(OEt2)2] > react with hydrazobenzene NH(Ph)NHPh and hydrazine or phenyUiydrazine according to the reactions in Scheme 32 to furnish cyclic bis(carbene) and cyclic carbene-imidoyl compounds . ... 

Hydrazine, MeN2H3, and PhN2Hj react with [Fe(CNMe)g] to give [(MeNC)4Fe(C4H9RNJ] (R = H, Me, or Ph) in which the hydrazine has attacked two isocyanide ligands, as above, to produce the complex (53) with two planar three-co-ordinate carbon atoms. "... 

A. Burke, A. L. Balch, and J. H.Enemark, Palladium and Platinum Complexes Resulting from the Addition of Hydrazine to Coordinated Isocyanide, J. Am. Chem. Soc. 92,2555-2557 (1970). 

Hydrazine reacts with [Fe(CNMe)4]2+ to form the chelate (16) in which addition to two adjacent isocyanide ligands has taken place.321 Methylamine reacts322 in a related way to give (17), while reaction with ammonia results in the formation323 of a monodentate carbene complex (18). Methylation of [Fe(CN)2(phen)2] with Me2S04 yields [Fe(CNMe2)(phen)2],26 which reacts with hydrazine to give323 the tris chelate (19) in a similar fashion to the formation of (16). 

Reduction by Ethanolic Potassium Hydroxide. This reaction gives about the same results as hydrazine and sodium tetrahydridoborate. It gives excellent results in the preparation of the zerovalent complex isocyanides (127), phosphines, and phosphites (130). 

Reactions of Co-ordinated Ligands. The topic of the attack of pyridine at co-ordinated ethene and co-ordinated dienes in appropriate platinum(ii) complexes has already been alluded to in an earlier section. " The reaction of c -[PtCl2(p-tolyl isocyanide) 2] with methylhydrazine in dichloromethane, which gives a carbene complex, follows a two-term rate law of this type shown in equation (1). As usual the term is assigned to a solvolytic path, but here the term is attributed to bimolecular attack of the hydrazine at the co-ordinated isocyanide. There is some discussion... 

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