V. G. Nenaidenko

New Synthetic Capabilities of Sulfonium Salts

The review summarizes published data on the synthesis and reactivity of new functionally substituted sulfonium salts: dimethyl(trifluoromethylsulfonyloxy)sulfonium trifluoromethanesulfonate, dimethyl(trifluoromethylsulfonyl)sulfonium trifluoromethanesulfonate, various disulfonium dications, dimethyl sulfidesulfur trioxide complex, acyl(dimethyl)sulfonium salts, dimethyl(trifluoroacetyl)sulfonium salts, and boron trifluoride complexes with alkylthio-substituted acyl fluorides as intramolecular analogs of acylsulfonium salts. A theoretical approach is described, which explains electrophilic reactivity of sulfonium salts.

A novel reaction of double carbon-carbon bond formation: synthesis of 2,2-dichlorostyrenes

Currently, metal complex catalysis is one of the most intensely developing fields of organic chemistry. Great at tention is devoted to the oxidation of a wide range o f organic compounds by oxygen in the presence of copper-conta ining systems, i However, examples of using other oxidants in the presence of copper compounds are rather rare. 2 Polyhaloalkanes (most often, carbon tetrachloride) can act as such oxidants. 3-8 We found a novel redox reaction of double carboncarbon bond formation catalyzed by copper salts, which permits the preparat ion of 2,2-dichlorostyrenes from N-unsubstituted hydrazones of aromatic aldehydes.

Reaction of catalytic olefination of hydrazones with polyhaloalkanes. Investigation of alkene formation chemoselectivity

Hydrazones of carbonyl compounds at treatment with polyhaloalkanes in the presence of CuCl as catalyst are converted into substituted alkenes with formation of a new C=C bond.

Organic chemistry. History and mutual relations of universities of Russia

The review describes the history of development of organic chemistry in higher schools of Russia over a period of 170 years, since the emergence of organic chemistry in our country till now.

New Synthesis of β-Iodostyrenes

A general procedure for the synthesis of β-iodostyrenes is proposed. Aromatic aldehyde and ketone hydrazones are converted into the corresponding β-iodostyrenes by treatment with CHI3 in the presence of a catalytic amount of CuCl.

Catalytic olefination reaction of carbonyl compounds. A study on stereoselectivity of alkene formation

The mechanism of formation of alkene stereoisomers in the catalytic olefination reaction of carbonyl compounds was studied. 4-Chlorobenzaldehyde hydrazone 1 stereoselectively reacts with a number of F-, Cl-, Br-, and I-containing polyhaloalkanes in the presence of catalytic amounts of CuCl to give ω-substituted styrenes 2 with the more thermodynamically stable alkene isomer being the major product. A model for the formation of the stereoisomers of alkenes 2 in the olefination reaction is proposed. Stereoselectivity of the reaction is determined by elimination of copper(ii) halides from the lowest-lying conformers of organocopper intermediates II. According to quantum-chemical calculations, the elimination should involve the staggered conformations with antiperiplanar arrangement of C—Hal and C—Cu bonds and proceed by the E2 anti-elimination mechanism. The results of quantum-chemical calculations are in good agreement with the experimental E/Z alkene isomer ratios.

Acylation of Cyclopropyl-Substituted Alkenes with Complexes Formed by ω-(Ethylthio)alkanoyl Fluorides and Boron Trifluoride

Cyclopropyl-substituted alkenes react with complexes formed by boron trifluoride and 3-(ethylthio)propionyl fluoride and 2-(ethylthio)acetyl fluoride to give ketones containing an ethylthio group. In most cases the reaction is not accompanied by opening of the three-membered ring or rearrangements.

Synthetic potentialities of sulfonylsulfonium salts: A new approach to the preparation of disulfonium dications

A new efficient method for the generation of disulfonium dications whose subsequent hydrolysis selectively affords monosulfoxides was developed based on the oxidation of bissulfides by trifluoromethanesulfonic anhydride.

Modern Trends of Organic Chemistry in Russian Universities

This review is devoted to the scientific achievements of the departments of organic chemistry in higher schools of Russia within the past decade.

Effect of the catalyst nature and quantity on catalytic olefination

The study of the catalyst nature effect on the catalytic olefination of 4-chlorobenzaldehyde hydrazone by polyhaloalkanes revealed that the best catalysts for the reaction are copper salts. With polyhaloalkanes more active than CCl4, like CBr4 and CCl3Br, the olefination can proceed without catalyst.