I. B. Rozentsveig

A novel regiospecific cascade synthesis of sulfonamide derivatives from N-(2-polychloroethyl)sulfonamides via chloroaziridine intermediates in the presence of mercaptoethanol

N-(1-Aryl-2-polychloroethyl)arenesulfonamides obtained on the basis of N,N-dichlorosulfoamides and polychloroethenes or phenylacetylene undergo a reaction cascade in the presence of mercaptoethanol. The reaction cascade opens a new route to the series of cyclic or open-chain sulfonamide derivatives. The process includes cyclization to aziridine intermediates, their further recyclization, and isomerization to imidoylchlorides or chloroimines, followed by substitution or reduction under the action of mercaptoethanol or hydrolysis. The final sulfonamide structures depend on the starting N-(polychloroethyl)sulfonamides. N-(2,2-Dichloroethyl)sulfonamides were transformed into sulfonamide-containing 1,4-oxathians while N-(2,2,2-trichloroethyl)sulfonamides were converted to N-(2-arylacetyl)arenesulfonamides. N-(2-Phenyl-2,2-dichloroethyl)sulfonamides form enamide derivatives that were transformed into aromatic ketones.

N-(2,2-Dichloro-2-phenylethylidene)arenesulfonamides in reactions with secondary amines

N-(2,2-Dichloro-2-phenylethylidene)arenesulfonamides were synthesized by a modified procedure, and their reactions with secondary amines were studied for the first time. Reactions of imines with dialkylamines proceed at room temperature to afford α,α-dichloromethylbenzene and N,N-dialkyl-N′-(arenesulfonyl)formamidines arising from the haloform cleavage of the initially formed unstable N-(1-dialkylamino-2,2-dichloro-2-phenylethyl)arenesulfonamides. When the reaction is carried out upon cooling to 0°C, the products of the nucleophilic addition of secondary amines to azomethines, N-(1-dialkylamino-2,2-dichloro-2-phenylethyl) are formed in yields of no higher than 5%. Nonempirical calculations of 13C-1H spin-spin coupling constants and their experimental measurements for the series of the synthesized N-arenesulfonamides were performed to show that these compounds exist in solutions exclusively as E isomers. Preferable conformations of the investigated compounds and the relative energies of their E and Z isomers in the gas phase were determined by quantum-chemical calculations at the MP2/6-311G** level of theory. The NMR spectral data revealed restricted rotation of the N,N-dialkylamino group about the partially double C-NAlk2 bond in the molecules of N-arenesulfonylformamidines.

Reactions of N-(Polychloroethylidene)arene-and - trifluoromethanesulfonamides with indoles

N-(Polychloroethylidene)arene-and -trifluoromethanesulfonamides reacted with indole and N-substituted indoles to give the corresponding N-[2,2-dichloro(or 2,2,2-trichloro)-1-(1H-indol-3-yl)ethyl]-substituted sulfonamides. Unlike N-(2,2,2-trichloroethylidene)trifluoromethanesulfonamide, less electrophilic N-(poly-chloroethylidene)arenesulfonamides failed to react with 1-(4-nitrophenyl)-1H-indole. Previously unknown N,N’-bis(2,2-dichloroethylidene)biphenyl-4,4’-disulfonamide reacted with 1-benzyl-1H-indole at both azomethine fragments. Likewise, reactions of 1,6-bis(1H-indol-1-yl)hexane and 1,4-bis(1H-indol-1-ylmethyl)-benzene with N-sulfonyl trichloroacetaldehyde imines involved both indole rings in the former.

Synthesis and Properties of N-(2,2,2-Trichloroethylidene)trifluoromethanesulfonamide and Its Derivatives

The reaction of N,N-dichloromethanesulfonamide with trichloroethylene gave N-(2,2,2-trichloro- ethylidene)trifluoromethanesulfonamide which showed high reactivity toward oxygen- and nitrogen-centered nucleophiles, as well as in C-alkylation of aromatic compounds.

Reactions of N-(2,2-Dichloro-2-phenylethylidene)arenesulfonamides with Aromatic and Heterocyclic Compounds

Benzene, toluene, and 2-chlorothiophene regioselectively react with N-(2,2-dichloro-2-phenyl- ethylidene)arenesulfonamides in the presence of oleum to give N-[1-aryl(or hetaryl)-2,2-dichloro-2-phenylethyl]arenesulfonamides. Analogous C-amidoalkylation products are formed by the action of N-(2,2-dichloro- 1-hydroxy-2-phenylethyl)- and N-(1-arylsulfonylamino-2,2-dichloro-2-phenylethyl)arenesulfonamides on toluene and 2-chlorothiophene in concentrated sulfuric acid.

Synthesis of unsaturated organoselenium compounds via the reaction of organic diselenides with 2,3-dichloro-1-propene in the hydrazine hydrate-KOH system

Dimethyldiselenide reacts with 2,3-dichloro-1-propene at 20–25°C in the hydrazine hydrate-KOH medium to form 2-chloro-3-methylselanyl-1-propene with 90% yield. Diphenyldiselenide in the reaction with 2,3-dichloro-1-propene, depending on the conditions, can give quite selectively four products: 2-chloro-3-phenylselanyl-1-propene, phenylselanylpropadiene, 1-phenylselanyl-1-propyne, and Z-1,2-bis(phenylselanyl)-1-propene. The effect of the selenium atom on the reaction direction and the products structure is discussed.

A Copper–Nitroxide Adduct Exhibiting Separate Single Crystal-to-Single Crystal Polymerization–Depolymerization and Spin Crossover Transitions

A complex cascade of solid-state processes initiated by variation of temperature was found for the heterospin complex [Cu(hfac)2L(Me/Et)] formed in the reaction of copper(II) hexafluoroacetylacetonate [Cu(hfac)2] with stable nitronyl nitroxide 2-(1-methyl-3-ethyl-1H-pyrazol-4-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl (L(Me/Et)). The cooling of the compound below 260 K initiated a solid-state chemical reaction, which led to a depolymerization of chains and formation of a pair heterospin complex [Cu(hfac)2L(Me/Et)2][[Cu(hfac)2]3L(Me/Et)2]. Further decrease in temperature below 144 K led to a spin transition accompanied by a drastic decrease in the effective magnetic moment from 2.52 to 2.24 μB. When the compound was heated, the order of effects was reversed: at first, the magnetic moment abruptly increased, and then the molecular fragments of the pair cluster united into polymer chains. Two hysteresis loops correspond to this cascade of temperature-induced structural transformations on the experimental dependence μeff(T): one at high (T↑ = 283 K and T↓ = 260 K) and the other at low (T↑ = 161 K, T↓ = 144 K) temperature. The spin transitions were also recorded for the [[Cu(hfac)2]3L(Bu/Et)2] and [[Cu(hfac)2]5L(Bu/Et)4] molecular complexes, which are models of the trinuclear fragment of the {[Cu(hfac)2]3L(Me/Et)2} pair cluster.

Synthesis and Properties of N-(2,2,2-Trichloroethylidene)- and N-(2,2,2-Trichloroethyl)nitrobenzenesulfonamides

Highly reactive N-(2,2,2-trichloroethylidene)nitrobenzenesulfonamides were synthesized by reaction of N,N-dichloronitrobenzenesulfonamides with trichloroethylene. Reactions of N-(2,2,2-trichloroethylidene)nitrobenzenesulfonamides with oxygen and nitrogen nucleophiles gave products of addition at the double CÍN bond; with arenes and haloarenes, the corresponding C-amidoalkylation products were obtained.

Features of the synthesis of unsaturated sulfides proceeding from (2-chloroprop-2-en-1-yl)isothiouronium chloride

Procedure of synthesis of sulfides containing a chloropropenyl fragment sensitive to bases was modified. The change in the sequence of reagents addition ensuring a contact of isothiouronium salt with a minimal base quantity and the application of a mixture hydrazine hydrate-alkali allowed the preparation of target sulfides under mild conditions in up to 93% yields.

Microwave-assisted synthesis of 2,5-diarylthiazolo[5,4-d]thiazoles from benzaldehydes and dithiooxamide

One-pot condensation of dithiooxamide with aromatic aldehydes and subsequent oxidation of intermediate 2,5-dihydro[1,3]thiazolo[5,4-d][1,3]thiazoles with selenium dioxide afforded 2,6-diaryl[1,3]thiazolo-[5,4-d][1,3]thiazoles which were characterized by 1H and 13C NMR, IR, and X-ray diffraction data.