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Registration Number

0218U007155, 0117U003549 , R & D reports

Title

Synthesis of novel heterocyclic carbenes & their metal complexes as catalysts for cyanation & trifluoromethylation reactions of organic compounds

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Head

Sabierov Vahiz Shamilievich,

Registration Date

20-12-2018

Organization

Institute of Organic Chemistry National Academy of Sciences of the Ukraine

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T. The object of the research is new stable carbenes and their metal complexes containing active functional groups (CN, CF3), directly linked to the metal atom to create catalysts for the functionalization reaction of organic compounds (cyanation, trifluoromethylation). The aim of the work is to obtain carbene complexes of transition metals (copper(I), palladium(II)) of the imidazole, benzimidazole and triazole series of a new type, containing active functional groups (CN, CF3), directly connected with the metal atom. Catalysis of functionalization reactions of organic compounds (cyanidation, trifluoromethylation). The research methods are synthetic, spectral (NMR spectroscopy), analytical (chromatographic, elemental analysis), X-ray structural analysis. R & D results: A new carbene complex of sterically hindered 1,3-bis-(2,6-dibenzhydrylphenyl-4-ethyl)-substituted imidazol-2-ylidene with trifluoromethyl copper(I) was obtained by reacting 1,3-bis-(2,6-dibenzhydrylphenyl-4-ethyl)-imidazol-2-ylidene copper(I) tert-butoxide with trimethylsilyl trifluoromethane. New carbene complexes of cyanide and trifluoromethylcooper(I) were synthesized on the basis of 1,3-dimethyl- and 1,3- (2,6-diisopropylphenyl)phenanthro[9,10-d]-imidazol-2-ylidene from the corresponding azolium salts by in situ reaction with potassium tert-butoxide and copper(I) cyanide in THF. By the interaction of 1-(2-hydroxyphenyl)-3-alkyl(aryl)benzimidazolium bromides with potassium tert-butoxide and copper(I) cyanide or palladium iodide new chelate carbene complexes of copper(I) and palladium(II) were obtained for the first time. The in situ reaction of 1,2,3,5-tetramezylimidazol-4-ylidene, obtained from 1,2,3,5-tetramezylimidazolium perchlorate and potassium hexamethyldisilazanide, with metal halides produced new mesoionic carbene complexes of copper(I) and palladium (II). Catalysis of the cyanation reaction of halo(het)arenes by carbene complexes of copper(I) in equimolar and catalytic amounts was studied. The use of sterically shielded 1,3-bis-(2,6-dibenzhydrylphenyl-4-ethyl)-imidazol-2-ylidene copper(I) cyanide was found to allow maximum performance of TON = 1000, TOF = 50 h-1 in the cyanation reaction of iodobenzene with trimethylsilyl cyanide in the N-methylpyrrolidone media at 80 °C. The method allows cyanation in the presence of labile functional groups in the halo(het)arenes. The effect of solvent on the efficiency of catalysis was studied. So, the maximum efficiency is observed in highly solvating solvents (N-methylpyrrolidone, N,N'-dimethylacetamide), the minimum in "inert" solvents (toluene, dioxane). A highly effective catalyst for the trifluoromethylation reaction of a halo(het)arenes - 1,3-bis-(2,6-dibenzhydryl-phenyl-4-ethyl)-imidazol-2-ylidene copper(I) trifluoromethyl, both equimolarly and in catalytic amounts, was found. When using 1 mol% of the catalyst at room temperature, the maximum values of TON = 95, TOF = 4 h-1 in the trifluoromethylation of iodobenzene are achieved in the N-methylpyrrolidone media. The data obtained are of importance for the development of the catalysis study of the haloarenes cyanation and trifluoromethylation reactions. The industry of application is the pharmaceutical industry (catalysis of the haloarenes cyanation and trifluoromethylation reactions), the synthesis of stable carbenes and their metal complexes.

Product Description

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Авксент'єв Олександр Сергійович

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2020-04-02