Knishevitsky A. Synthesis and transformations of stable carbenes and carbenoids which contain the amidine fragment

Object - conjugated, bridged, 4,4'-substituted arylenebiscarbenes of 1,2,4-triazole series, monocarbenes of imidazole series, six-membered cyclic and acyclic tetraalkylamidinium salts, 2H-azolines of 1,2,3,4-tetrahydropyrimidine and perhydropyrimidine series. The goal of the work is synthesis and study of the new types of stable carbenes of 1,2,4-triazole, imidazole series, cyclic and acyclic diaminocarbenes, and also cryptocarbenes of benzimidazole series. Methods of the research are synthetic organic chemistry, thin layer chromatography, elemental analysis, IR-, NMR- and mass-spectroscopy, X-ray diffraction study. The new types of stable carbenes are synthesized: 4,4'-linked bridged arylenebiscarbenes of 1,2,4-triazole and 1,3-dialkyl-4,5-diaryl-imidazole-2-ylidene series and their metal complexes with copper and silver from the simple organic compounds - 1,3,4-oxadiazoles and imidazoles. The first syntheses of 1-adamantyl-substituted cyclic and acyclic amidinium salts were carried out from 1-aminoadamantane and 1-bromoadamantane. Two pathways of transformations of adamantylsubstituted diaminocarbenes with alifatic nitriles have been found: 1) C-H insertion (cyclic diaminocarbenes); 2) nucleophilic substitution of amino-group on cyanomethyl fragment to form dialkylaminoacrylonitriles (acyclic diaminocarbene). Cryptocarbene properties of 2-cyanomethylazolines have been demonstrated in the case of 1,3-dibenzyl-2-cyanomethyl-2H-benzimidazoline reactions with organic electrophiles. The area of application is the preparation of new types of carbenes and metal carbene complexes as the reagents for organic synthesis and potential catalysts in organic reactions.