Quantum Chemical and Experimental Studies of an Unprecedented Reaction Pathway of Nucleophilic Substitution of 2-Bromomethyl-1,3-thiaselenole with 1,3-Benzothiazole-2-thiol Proceeding Stepwise at Three Different Centers of Seleniranium Intermediates

The results of quantum chemical and experimental studies of the reaction of 2-bromomethyl-1,3-thiaselenole with 1,3-benzothiazole-2-thiol made it possible to discover the unprecedented pathway of this reaction, which proceeds stepwise at three different centers of seleniranium intermediates. The first stage includes an attack of thiolate anion at the selenium atom of the seleniranium cation accompanied by ring opening with the formation of (Z)-2-[(1,3-benzothiazol-2-ylsulfanyl)selanyl]ethenyl vinyl sulfide, which is converted to six-membered heterocycle, 2-(2,3-dihydro-1,4-thiaselenin-2-ylsulfanyl)-1,3-benzothiazole, in a 99% yield. The latter compound undergoes rearrangement with ring contraction producing five-membered heterocycle, 2-[(1,3-thiaselenol-2-ylmethyl)sulfanyl]-1,3-benzothiazole, in a 99% yield (the thermodynamic product). The formation of 1,2-bis[(Z)-2-(vinylsulfanyl)ethenyl] diselenide is the result of the disproportionation of (Z)-2-[(1,3-benzothiazol-2-ylsulfanyl)selanyl]ethenyl vinyl sulfide. Thus, based on the quantum chemical and experimental studies, a regioselective synthesis of the reaction products in high yields was developed.

Efficient Regioselective Synthesis of Novel Water-Soluble 2H,3H-[1,4]thiazino[2,3,4-ij]quinolin-4-ium Derivatives by Annulation Reactions of 8-quinolinesulfenyl Halides

Regioselective synthesis of novel 2H,3H-[1,4]thiazino[2,3,4-ij]quinolin-4-ium derivatives has been developed by annulation reactions of 8-quinolinesulfenyl halides with vinyl chalcogenides (vinyl ethers, divinyl sulfide, divinyl selenide and phenyl vinyl sulfide) and tetravinyl silane. The novel reagent 8-quinolinesulfenyl bromide was used in the annulation reactions. The influence of the substrate structure and the nature of heteroatoms on the direction of the reactions and on product yields has been studied. The opposite regiochemistry was observed in the reactions with vinyl chalcogenides and tetravinyl silane. The obtained condensed heterocycles are novel water-soluble functionalized compounds with promising biological activity.

Sodium iodide-mediated synthesis of vinyl sulfides and vinyl sulfones with solvent-controlled chemical selectivity

Solvent-controlled selectivity of the elimination/coupling reaction was realized for divergent synthesis of vinyl sulfides and vinyl sulfones. The described protocol is more convenient for the preparation of vinyl sulfide and vinyl sulfone related skeletons.

A Non aqueous Formulation for Efficient Detoxification of Chemical Weapons at Sub zero Temperatures

An effective decontamination methodology based on nucleophilic non-aqueous decontaminant has been developed against chemical weapons sulfur mustard and soman. This new formulation consists of non-aqueous solution of 2-aminoethanol (60%, w/v), potassium hydroxide (2%, w/v), and N-methyl-2-pyrrolidone (38 %, w/v) and detoxified more than 99 % of sulfur mustard and soman within a period of 30 min at -35 °C. It was found to be operable over a wide range of temperatures starting from -35 °C to +55 °C without losing its fluidity and detoxicant efficiency at sub-zero temperatures promising hassle-free application against chemical weapons. It degrades sulfur mustard to divinyl sulfide and 2-chloroethyl vinyl sulfide and converted soman into O-pinacolyl O’-(2-amino) ethyl methylphosphonate, which are relatively non toxic to humans. This formulation is environmentally benign, relatively non corrosive and has an improved capability to dissolve and decontaminate chemical weapons within 15 minutes at ambient conditions. This approach paves the way for efficient and rapid decontamination platform for chemical weapons and holds considerable promise for field application in near future.

Phosphine catalyzed [3+2] cyclization/Michael addition of allenoate with CS2 to form 2-thineyl vinyl sulfide

We have developed a DPPE-catalyzed three molecular two component tandem reaction of γ-substituted allenoate and CS2 to construct 2-thineyl vinyl sulfide through phosphine catalyzed [3+2] cyclization followed by Michael addition.

Cationic copolymerization of cholesterol vinyl ether with methylvinylsulfide: toward medicinal polymers

Oligomers of cholesterol vinyl ether (CVE) with methyl vinyl sulfide synthesized in the presence of cationic catalyst ВF3 OEt2 in up to 81% yield (Mn up to 5700) demonstrate optical activity exceeding that of CVE homopolymer, which is probably due to both conformational effects of the oligomer chain and chirality induction during the polymerization.