Cyanamide complexes

Cyanamide Complexes as Combustion Catalysts from Composite Propellants. See under Combustion Rate (or Burning Rate) Catalysts... 

Palladium-mediated cydization based on the reactivity of o-alkynyl or alkenyl-phenyl isonitriles have been developed [105]. On the basis of their earlier studies on the three-component synthesis of allyl aryl cyanamides [106], Yamamoto and co-workers reported a palladium-catalyzed three-component coupling reaction of 2-alkynylisocyanobenzenes 122 with allyl methyl carbonate and trimethylsilylazide leading to N-cyanoindoles 125 [107]. One of the key steps of the proposed mechanism is the formation of 7i-allylpalladium carbodiimide 123 and its isomerization to rc-allylpalladium cyanamide complex 124 (Scheme 8.50). 

Cyanamides are pseudo-halide nitrogen ligands that are readily coordinated to metals. A novel compound is 2-cyanaminofluoren-9-one (HL4)24. Its thallium salt T1+(L4)-(Scheme 7) is useful as a transmetallating agent in a reaction with trimethyltin chloride to produce the corresponding tin cyanamide complex [SnMe3L4] (Scheme 8). 

Kamijo and Yamamoto developed a palladium-catalyzed three-component synthesis of N-cyanoindoles (131) (Scheme 5.39) [81]. The reaction of a 2-alkynyliso-cyanobenzene (132), allyl methyl carbonate, and trimethylsilylazide in the presence of Pd2(dba)3 (2.5 mol%) and tri(2-furyl)phosphine (10 mol%) at 100 °C afforded the N-cyanoindoles 131 in good yield. Key steps of this reaction involved the formation of jt-allylpalladium complex 133, its Curtius-like rearrangement to intermediate 134, and subsequent isomerization to the Jt-allylpalladium cyanamide complex 135. A wide range of functional groups is tolerated at the para, meta, and even ortho positions of the aromatic ring. 

Such criteria cannot be simultaneously satisfied in the case of the NHa group. Studies have thus been undertaken to examine the mode of interaction of complexes where such a group is the potential bridging site. The reductions of penta-ammine cobalt complexes of urea, carbamate, N-cyanoguanidine [N=C—N=C(NH2)2l, and cyanamide (N=C—NHa), by chromium(n) involve an outer-sphere path with the exception of the carbamato-species, where, however, there is no evidence of a nitrogen-bonded chromium(in) species as product. The cyanamide-complex reaction follows the rate law... 

Traces of cyanamide can be deterrnined colorknetricaHy by complex formation with l,2-naphthaquinone-4-sodium sulfonate (4). 

The aqueous decomposition of thiourea to sulfide and cyanamide has been found to be catalyzed by metal hydroxide species and colloidal metal hydroxide precipitates. Kitaev suggested that Cd(OH)2 is actually required for CdS film formation to occur by adsorption of thiourea on the metal hydroxide particles, followed by decomposition of the Cd(OH)2-thiourea complex to CdS. Kaur et al. [241] found... 

Bardaji, M., Laguna, A., Perez, M.R. and Jones, P.G. (2002) Unexpected ring-opening reaction to a new cyanamide-fhiolate ligand stabilized as a dinuclear gold complex. Organometallics, 21, 1877. 

The treatment of 2-amino-4,5-dihydrothiazole with [Au(ACAC)(PPh3)] evolves to an unprecedented ring-opening reaction to give the new ligand (2-cyanamide)ethylthiolate, stabilized as the dinuclear gold complex (Equation (42)).2315... 

Homo- and heteroleptic complexes of Cd alone and of Cd and Hg with the ligand dicyanamide (dca) N(CN)2-, homologous to cyanamide NCN2-, have been studied in various solvents (formation constants of the complexes [M(dca) ](" 2> (M = Cd, Hg l < n < 4)), with the result that the complexes of Hg are more stable than those of Cd. Otherwise, obviously no studies on the isolated compounds M(dca)2 or on homoleptic complexes derived therefrom have been published. 

Lewis C. E. (American Cyanamid). Boron Complexes of o,o -DiHydroxyPhenylAzoNaphthyl Dyes. U.S. Patent 3726,854, April 10 1973. 

The major use of sodium cyanamide is in the production of sodium cyanide, a compound that is used extensively in preparing solutions for the electroplating of metals. Another use for NaCN is in extraction processes employed to separate gold and silver from ores as a result of their forming complexes with CN . Sodium cyanide, an extremely toxic compound, is also used in the process known as case-hardening of steel. In this process, the object to be hardened is heated and allowed to react with the cyanide to form a layer of metal carbide on the surface. 

The constituent of paint, 2-nitropropane, exhibiting genotoxicity and hepatocarcinogeni-city was oxidized by liver microsomes forming nitric oxide, which was identified as a ferrous NO complex [61]. Clement et al. [62] concluded that superoxide may participate in the microsomal oxidation of /Y-hydroxyguanidincs, which produced nitric oxide, urea, and the cyanamide derivative. Caro et al. [63] suggested that the oxidation of ketoxime acetoxime to nitric oxide by microsomes enriched with P-450 isoforms might be mediated by hydroxyl or hydroxyl-like radicals. 

Creosol, 33, 17 Crotonaldehyde, 33, IS 34, 29 diethyl acetal, 32, 5 Cupric acetate monohydrate, 36, 77 Cuprous oxide-silver oxide, 36, 36, 37 Cyanamide, 34, 67 36, 8 Cyanoacetamide, 32, 34 Cyanoacetic acid, 31, 25 Cyanoacetylurea, 37, 16 >-Cyanobenzaldehyde, 30, 100 >-Cyanobenzaldiacetate, 36, 59 3-Cyano-5,6-dimethyl-2(l)-pyridone, 32,34 N-2-Cyanoethylaniline, 36, 6 N-2-Cyanoethyl- -anisidine, 36, 7 Cyanoethylation, of aniline, 36, 6 of ethyl phenylcyanoacetate, 30, 80 N-2-Cyanoethyl-m-chloroaniline, 36, 7 Cyanogen, 32, 31 Cyanogen iodide, 32, 29 Cyanogen iodide, complex with sodium iodide, 32, 31... 

We are investigating the template formation of 2-D and 3-D metal-di-cyanamide anionic networks, for instance of type Mn(dca)3, by use of [M(N,N)3]n+ cations such as [M(2,2 -bipy)3]2+. A hexagonal sheet network was formed in [Fen(2,2 -bipy)3][Fen(dca)3]2 in which the cations fitted beautifully within the hexagonal windows. The cation remained LS between 4-300 K [66], Attempts to make the Con(2,2 -bipy)32+ analogue unfortunately led to dissociation of dca and bipy and formation of a zig-zag chain structure in the weakly-coupled HS complex [Con(dca)2(2,2 -bipy)2]n. The complex [Fen(propyl-tetrazole)6]2+, which has a very sharp SCO transition [42], unfortunately did not yield a network product. 

With acetone and hydrogen chloride, cyanoguanidine forms the addition compound II this jdelds melamine on treatment with alkalis at room temperature, cyanamide being eliminated. In the presence of copper or nickel hydroxide, an intermediate cyanobiguanide-complex salt can be isolated, and converted by dilute nitric acid at 20° into cyanobiguanide... 

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