2- -l,3-dithiols

Several workers have studied the reactions of l,2-dithiole-3-thiones and related systems with acetylenic esters. The thiones (395), for example, react with DMAD to give 2-thioacylmethylene-l,3-dithioles (396), which may arise through a concerted 1,3-dipolar addition to the S—C=S moiety. These adducts undergo further reaction with DMAD, yielding thiopyran-4-spiro-2 -(l,3-dithioles) (397) (Scheme 62). Similarly, the reaction of 5-phenyl-l,2,4-dithiazole-3-thione (398) with... 

Similar to the 1,2-dithiolium system (see 1,2,3-dithiazines, Section 1.4.1.1.2.), l,3-dithiol-2-ium cations undergo ring enlargement by treatment with ammonia/iodine to give 1,4,2-dithiazines... 

Dithiole, 2-(l,3-dithiol-2-ylidene)-, compd. with iron chloride oxide (FeClO) (2 17), 30 177 [158188-73-9], Iron chloride oxide (FeClO), compd. with pyridine (1 1), 30 182 [158188-74-0], Ytterbate(3—). tri-(i-bromo-hexabromodi-, trirubidium, 30 79... 

Recently, it has been reported that l,3-dithiole-2-thione (12) reacts with primary amine to give the corresponding thiourea and A-4-thia2oline-2-thione (Scheme 5) (14). 5-Methylenethiazolidine-2-thione (13) obtained from the reaction of propargyl amine and carbon disulfide... 

Thermolysis of the 1,2,3-thiadiazoles (545) in the presence of carbon disulfide leads to the thiocarbonyl carbene (546) adduct, the ring-fused l,3-dithiole-2-thione (547) (76JOC730). 

Thieno[3,4-d][l,3]dithiol-2-one, 1-nitro-synthesis, 6, 1013 Thieno[3,4-c]furan, 4,6-dichloro-synthesis, 6, 1013 Thieno[3,4-c]furan, tetraphenyl-formation, 4, 1060 synthesis, 4, 1060 UV spectra, 4, 1044 Thieno[3,2-6]furans structure, 4, 1039 synthesis, 6, 1020 Thieno[3,4-c]furans... 

Carbon disulfide can act as an electrophilic agent with enamines at room temperature. Therefore, treatment of an enamine with both elemental sulfur and carbon disulfide in a polar solvent can result in the formation of a 3H-l,2-dithiole-3-thione (such as 108) and/or a 2H-l,3-dithiole-2-thione (such as 109) (135,139,140). These products are the result of competing... 

Sulfur has also been added to the condensation product of enamines with cyanoacetic ester (575) and directly to enamines (576). A 2H-l,3-dithiol-2-thione was obtained from morpholinocyclohexene and tetramethylthiuram disulfide (577). 

Both CSs and CSs were also successfully generated by the fragmentation of ionized 4,5-dioxo-2-thioxo-l,3-dithione (65) and 2-thioxo-l,3-dithiole (66) (90JA3750). Tire three sulfur atoms in the anion and cation radicals were chemically equivalent, suggesting that they take the D h (or C2u) form (67 or 68). On the other hand, under similar conditions, 3-thioxo-1,2-dithiole (69) yielded two isomeric cation radicals the (or 2 ) form and the carbon disulfide 5-sulfide form (70). Ab initio calculations on three electronic states of CS3 at the 6-31G -l-ZPVE level indicated that the C21, form (68) was more stable than the carbon disulfide 5-sulfide form (70) in the neutral (both singlet and triplet states) and the anion radical states, but 68 was less stable than 70 in the radical cation state. 

Iodoquinoxaline and 4-methyl-5-tributylstannyl-l,3-dithiol-2-one gave 2-(2-0X0-5 -methyl-1,3 -dithiol-4-yl)quinoxaline (63) (l-methyl-2-pyrrolidinone, 5°C, CuTC i, A, 40 min 44%). ... 

Ethynylquinoxalme (144) and bis(isopropoxythiocarbonyl) disulfide (145) gave 2-(2-oxo-l,3-dithiol-3-yl)quinoxalme (146) [l,l -azo(cyclohexanecar-bonitrile), PhMe, reflux, N2, 7 h 77%] somewhat similarly, 2-(acetylethy-nyl)quinoxaline and 4-phenyl-l,3-dithiolane-2-thione gave 2-(5-acetyl-2-... 

A range of 4-substituted l,3-dithiole-2-thiones (71) and 2,6-substituted 1,4-dithiafulvalenes (73) were synthesised from 4-substimted 1,2,3-thiadiazoles (72). Reaction of (72) with NaH in a mixture of CS2 and acetonitrile led to the formation of (71), whereas absence of CS2 gave fulvalenes (73). This route was found to be very efficient for the preparation of 4-formyl-1,3-dithiole-2-thione (71 R = CHO), which was previously difficult to prepare, and thus allowed the synthesis of the novel 2,6(7)-bisformyltetraAiafulvalene (74) <96T3171>. 

In the synthesis of l,3-dithiolan-2-ones from spirocyclic intermediates, via episulfides, substituted tetrathiacyclododecane and the related pentathiacyclopentadecane were isolated in good yields <96JCS(P1)289>. Preparation and molecular dynamics studies of 2,5,8,17,20,23-hexathia[9.9]-p-cyclophane have been reported <96P4203>. The syntheses and properties of thiocrowned l,3-dithiole-2-thiones and their conversion to tetrathiafiilvenes via treatment with triethylphosphine have been described <96LA551>. 

Condensation of dicesium 2-thioxo-l,3-dithiole-4,5-diselenolate with fo/s-alkylating polythioethers under high dilution conditions afforded the TTF-containing macrocycles possessing soft donor sites and 12-, 15-, and 18-membered rings <%JCS(P1)1995>. 

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