63812-28-2Relevant academic research and scientific papers
Diaminocarbene- and Fischer-carbene complexes of palladium and nickel by oxidative insertion: Preparation, structure, and catalytic activity
Kremzow, Doris,Seidel, Guenter,Lehmann, Christian W.,Fuerstner, Alois
, p. 1833 - 1853 (2005)
Oxidative insertion of [Pd(PPh3)4] or [Ni(cod) 2]/PPh3 into the C-Cl bond of various 2- chloroimidazolinium- and other -amidinium salts affords metal-diaminocarbene complexes in good to excellent yields. This procedure is complementary to existing methodology in which the central metal does not change its oxidation state, and therefore allows to incorporate carbene fragments that are difficult to access otherwise. The preparation of a variety of achiral as well as enantiomerically pure, chiral metal-NHC complexes (NHC = N-heterocyclic carbene) and metal complexes with acyclic diaminocarbene ligands illustrates this aspect. Furthermore it is shown that oxidative insertion also paves a way to prototype Fischer carbenes of PdII. Since the required starting materials are readily available from urea- or thiourea derivatives, this novel approach allows for substantial structural variations of the ligand backbone. The catalytic performance of the resulting library of nickel- and palladium-carbene complexes has been evaluated by applications to prototype Suzuki-, Heck-, and Kumada-Corriu cross-coupling reactions as well as Buchwald-Hartwig aminations. It was found that even Fischer carbenes show appreciable catalytic activity. Moreover, representative examples of all types of neutral and cationic metal-carbene complexes formed in this study have been characterized by X-ray crystallography.
The Reaction of N-Dichloromethylene-N,N-dimethylammonium Chloride (Vieche's Salt) with Thiophenols and Phenols: a Synthesis of Unsymmetrical Diaryl Carbonates
Copeland, Christopher,Stick, Robert V.
, p. 1483 - 1487 (2007/10/02)
The reaction of N-dichloromethylene-N,N-dimethylammonium chloride (Viehe's salt) with various thiophenols and phenols is reported.The resulting intermediate salts are generally transformed by water or sodium hydrogen sulfide to thiocarbonates and thiocarbamates.An efficient synthesis of unsymmetrical diaryl carbonates is discussed.
The Synthesis of Alkyl- and Aryl-Substituted 1,3,5-Triazines
Harris, Roger L. N.
, p. 623 - 634 (2007/10/02)
The reaction of chloromethyleneiminium salts with N-cyanoamidines provides a new and versatile route to alkyl- and aryl-substituted 1,3,5-triazines.Variation of substituents in the starting materials allows the synthesis of monoaryl-, diaryl-, alkyl-aryl- and certain mono- and di-alkyl-1,3,5-triazines bearing a variety of other substituents including hydrogen, chlorine and O-, S- and N-radicals.The generally good yields, ready availability of starting materials, and the scope and facility of the reaction make it the method of choice for the synthesis of 1,3,5-triazines with these substitution patterns.
