G. I. Nikishin

Bio: G. I. Nikishin is an academic researcher from Russian Academy of Sciences. The author has contributed to research in topics: Radical & Homolysis. The author has an hindex of 11, co-authored 280 publications receiving 540 citations.

Generation of ω-carbomethoxyalkyl radicals and syntheses based on them

Abstract: 1. The reaction of the esters of peroxydicarboxylic acids (CH3OOC(CH2)nCOO)2 with Fe(II) sulfate leads to the selective generation of ω-carbomethoxyalkyl radicals CH3OOC-(CH2)n, n=2-5, 7, 8, 10. 2. These radicals predominantly recombine under the influence of Fe(II) sulfate, while Cu(II) sulfate oxidizes them to the esters of the corresponding ω-unsaturated carboxylic acids, and Cu(II) chloride converts them to the esters of (ω-chlorocarboxylic acids.

Electrooxidation of alken-1-ylarenes in aqueous alcohol solutions

Abstract: In the initial stages of the electrooxidation of alken-1-ylarenes-propenyl-benzene (Ia) and 4-propenylanisole (Ib)- in aqueous alcohol solutions, 1,2-dialkoxypropyl- (II), 1-hydroxy-2-alkoxypropyl- (VII), and 1,2-dihydroxy-propyl arenes (VIII) are formed. Subsequent rupture of the C-C benzyl bond converts the ethers (II) into benzaldehyde acetals (III) and benzaldehydes (IV), and compounds (VII) and (VIII) into (IV). Benzaldehydes (IV) are also formed from (II) by hydrolysis of the acetals (III)- partly for (IIIa) and completely for (IIIb). Electrolysis of (Ia and Ib) in aqueous alcohol solution leads mainly to their conversion into benzaldehydes (IV).

A free-radical reaction of alkanoic acids with tetrachloroethylene

Abstract: The di-tert-butyl peroxide-initiated free-radical reaction of C3-C6 alkanoic acids with tetrachloroethylene results in the formation of a mixture of isomeric (trichlorovinyl)alkanoic acids with the predominant isomer bearing the trichlorovinyl group at the (ω−1) position.

Reaction of tetrachloroethylene with methanol under pressure

Abstract: A method was developed for the preparation of trichloroallyl alcohol from methanol and tetrachloroethylene in a titanium apparatus under a pressure of 100–120 atm in the presence of CC14 (335°), CH3COC2H5 (365°) or (CH3)3COOC (CH3)3 (185°), in a yield of 35–55% when based on starting TCE and 85–90% when based on reacted TCE, with a reactor output of up to 1000 g/h liter.

Rearrangement of sulfonamidyl radicals with hydrogen migration

Abstract: One-step outlying oxidative chlorination of alkanesulfonamides by the action of the Na/sub 2/S/sub 2/O/sub 8/-CuCl/sub 2/ system via intermediate sulfonamidyl radicals gives 3- and 4-chloroalkanesulfonamides. Rearrangements of sulfonamidyl radicals with H atom migration from the sulfonyl segment predominates over rearrangement with H atom migration from the amide segment.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Cobalt-Catalyzed C―H Activation

Abstract: Catalytic C–H activation has emerged as a powerful tool for sustainable syntheses. In the recent years, notable success was achieved with the development of cobalt-catalyzed C–H functionalizations with either in situ generated or single-component cobalt-complexes under mild reaction conditions. Herein, recent progress in the field of organometallic cobalt-catalyzed C–H activation is reviewed until November 2015.

Catalytic Enantioselective Transformations Involving C-H Bond Cleavage by Transition-Metal Complexes.

Abstract: The development of new methods for the direct functionalization of unactivated C–H bonds is ushering in a paradigm shift in the field of retrosynthetic analysis. In particular, the catalytic enantioselective functionalization of C–H bonds represents a highly atom- and step-economic approach toward the generation of structural complexity. However, as a result of their ubiquity and low reactivity, controlling both the chemo- and stereoselectivity of such processes constitutes a significant challenge. Herein we comprehensively review all asymmetric transition-metal-catalyzed methodologies that are believed to proceed via an inner-sphere-type mechanism, with an emphasis on the nature of stereochemistry generation. Our analysis serves to document the considerable and rapid progress within in the field, while also highlighting limitations of current methods.