S. Munavalli

Reactions of trifluoromethylthiocopper with halomethanes

Abstract The reaction of trifluoromethylthiocopper with halomethanes, namely di- and triiodo-, dibromodichloro-, dibromochlorofluoro-, dibromo-difluoro-,bromochlorofluoro-, phenyltrichloro-, bromocyano- and dibromofluoro-methanes, has been investigated in detail. In addition to the expected compounds, the formation of unusual products such as bis(trifluoromethyl)trithiocarbonate, dimethyl(trifluoromethylthio)benzene, bis(trifluoromethylthio)fluoromethane, (trifluoromethylthio)carbonyl fluoride, carbon disulfide, carbon tetrachloride, trifluoromethylthio- benzoate, etc. was observed. In some cases, bis(trifluoromethylthio)mercury has been used instead of trifluoromethylthiocopper. The mechanism of formation of the various products and their mass spectral fragmentation behavior are described.

Simultaneous scission of CS and SS bonds of bis(trifluoromethyl)trisulfide by Grignard reagents

Abstract Trifluoromethyl mono-, di- and tri-sulfides, and alkyl sulfides and disulfides, as well as dimerized products, are formed as a result of the simultaneous cleavage of the CS and SS bonds of bis(trifluoromethyl)trisulfide by Grignard reagents at − 78 °C. The formation of various products has been rationalized on the basis of the involvement of free radicals.

Single electron transfer catalyzed simultaneous cleavage of CS and SS bonds

Abstract Since the SS bond of polysulfides plays a vital role in biological processes, the chemistry of the SS bond has attracted considerable attention. The reaction of bis-(trifluoromethyl) trisulfide with organolithium reagents at −78 °C has now been found to cause simultaneous scissions of the CS and SS bonds and to furnish mixed monosulfides, disulfides and trisulfides containing the trifluoromethyl moiety. The formation of the various products has been rationalized on the basis of the involvement of the single electron transfer process.

Novel reactions of perfluoroalkylphenyl sulfides with organolithium reagents

Abstract The reaction of anisole with organolithium reagents, commonly known as ortho -directed metallation, is of considerable synthetic utility in organic chemistry and as such has attracted considerable attention in recent years. Over the past 50 years, several mechanisms have been proposed to account for the observed regioselective metallation. For the first time, the reaction of perfluoroalkylphenyl sulfides with organolithium reagents has been investigated and found to furnish products resulting from the replacement of the perfluoroalkyl moieties with alkyl groups derived from the metallating agents. Phenyltrifluoromethyl ether, the anisole analog, failed to undergo metallation. A rationalization for the formation of unusual products via mediation of a single-electron-transfer process is presented in this paper together with the spectral data of the products.

Synthesis and biological screening of trifluoromethylthioarsenicals

Abstract The title compounds have been prepared from the reaction of trifluoromethylthiocopper and alkyl mono- and di-haloarsines. This communication describes their synthesis, biological screening and mass spectral fragmentation behavior.

Phototrifluoromethylsulfenylation of phenylcyclopropane

Abstract Cyclopropane and its derivatives undergo reactions analogous to alkenes as well as free-radical reactions leading to products corresponding to ring-fission, ring-substitution and rearrangement reactions. When a solution of phenylcyclopropane and trifluoromethylsulfenyl chloride in acetonitrile is photolyzed, eight to ten compounds are formed in various amounts depending on the duration of the photolysis. The spectrometric characterization and the mechanism of formation of the various products are presented in this paper.

Unusual reaction of Grignard reagents with bis(trifluoromethyl) disulfide

Abstract Simultaneous scission of the CS and SS bonds of bis(trifluoromethyl)disulfide occurs on treatment with Grignard reagents at −78 °C and gives rise to unsymmetrical disulfides and sulfides as well as alkyl sulfides. Under similar experimental conditions, alkyl disulfides are recovered unreacted. Probable mechanisms of the cleavage reactions are presented.

Novel reactions of perfluoro-2-(trifluoromethyl)-propene

Abstract Unlike its hydrocarbon counterpart, perfluoro-2-(trifluoromethyl)propene is a highly reactive compound. It participates in both heterolytic and homolytic reactions. It readily reacts with nucleophiles and sluggishly with electrophiles. It reacts as well with common organic solvents, such as dimethylformamide, ethanol and others. In this communication, we describe its reactions with trifluoromethylthiocopper, sulfur trioxide and tributyltin cyanide, the mechanism of formation of the various products and their mass spectral data.

Synthesis of bis(trifluoromethyl)trisulfide and bis(trifluoromethylthio)selenide

Abstract The use of 4-dimethylaminopyridine as a catalyst in the reaction of trifluoromethylsulfenyl chloride with hydrogen sulfide at −78 °C cuts down the time of reaction from 30 d to 1 d and gives up to 70% yield of bis(trifluoromethyl)trisulfide (1). Similarly, bis(trifluoromethylthio)selenide (2) can be prepared from hydrogen selenide and trifluoromethylsulfenyl chloride. The influence of other catalysts on the course of the reaction, the formation of unusual by-products, the NMR and mass spectral data of 1 and 2 are presented in this paper.

Modified Ullmann coupling of 2-chloro-3-trifluoromethylpyridine

Abstract The application of the modified Ullmann reaction to 2-chloro-3-trifluoromethylpyridine furnishes 5,5′-bis(trifluoromethyl)-2,2′-bipyridine as the primary product, accompanied by small amounts of the expected 3,3′-bis(trifluoromethyl)-2,2′-bipyridine, 2-benzyl-3-(trifluoromethyl)pyridine, bibenzyl, 3-trifluoromethylpyridine, 3-methylpyridine, 2-hydroxyethyl-(3-trifluoromethylpyridyl) ether and 2-hydroxyethyl-(3-methylpyridyl) ether. For comparison purposes, a sample of 3,3′-bis-(trifluoromethyl)-2,2′-bipyridyl was prepared by the treatment of 2,2′-bipyridyl-3,3′-dicarboxylic acid with sulfur tetrafluoride. The formation of all but two compounds mentioned above can be rationalized on the basis of the single-electron-transfer process.