Trithiocarbonate 5,5-dioxide

Trithiocarbonate 5,5-dioxides are reduced to the trithiocarbonates by tetra-n-butylammonium borohydride at ca. -25°C [29]. 

Formation of 5-substituted 5-mercaptothiatriazoles from trithiocarbonate 5,5-dioxides (71CC314) or alkylthio- or arylthio-thiocarbonyl p-toluenesulfonyl disulfides reacting with azide ion has been reported (79CC1135) but these methods have not found any synthetic application. 

Cyanothioformamides NC-CS-NR1-C0R2 (R = Ph or 4-O2NC6H4 R = CF3 or Ph) comprise another class of reactive dienophiles (e.g. equation 40) . The trithiocarbon-ate 61 adds to cyclopentadiene to yield 62 (equation 41) 2 Trithiocarbonate 5, 5 -dioxides 63 (Ar = 4-MeCeH4 or d-ClCsPLt Ar = Ph or 4-CIC6H4) react instantly with cyclopentadiene to afford mixtures of endo- and exo-cycloadducts 64 and 65, respectively, in which the former predominate (eqnation 42). The adducts produced from acyclic dienes are unstable they readily eliminate arylsnUinic acids to yield thiopyrans (eqnation 43). ... 

Trithiocarbonate 5,5-dioxides 14 are also reactive thiocarbonyl dienophiles (Scheme 5-XIV). Addition of 14 to cyclopentadiene afforded a high yield of a 3 1 mixture of the endo and exo adducts. The corre-... 

Nilsson and Senning have recently described the formation of the interesting trithiocarbonate 5 5-dioxides (295) as the result of the reaction of dithiochloroformates with metal sulphinates. On the other hand, the reaction between phenyl dithiochloroformate and sodium methanesul-phinate afforded diphenyl trithiocarbonate and the compound (297) as the... 

Thiirenes have been isolated in argon matrices at 8 K by photolysis of 1,2,3-thiadiazoles or vinylene trithiocarbonates (Scheme 151) (80PAC1623, 8UA486). They are highly reactive and decompose to thioketenes and alkynes (Scheme 22). Electron withdrawing substituents stabilize thiirenes somewhat, but no known thiirene is stable at room temperature unlike the relatively stable thiirene 1-oxides and thiirene 1,1-dioxides. 

Vinylene sulfate — see 2,2-dioxide under 1,3,2-Dioxathiole Vinylene thiocarbonate synthesis, 6, 780 Vinylene trithiocarbonates photolysis, 7, 181 Violapterin... 

The Corey-Winter olefin synthesis is based on the stereospecific loss of carbon dioxide or carbon disulfide from the carbenes formed by treatment with bivalent organophosphorus compounds of thionocarbonates or trithiocarbonates [218-220]. 

Another example which illustrates the importance of the structure of the diazoalkane in reactions of thiocarbonyl compounds and derivatives thereof is the reaction of trithiocarbonate S,S-dioxide 6 with diazomethane and phenyldiazomethane52. Whereas the former gives the dithiolane derivative 7, the latter affords the thiirane 8. Both reactions are, however, fully stereoselective affording single diastereomeric compounds the most probable structures are depicted in the scheme. 

Breakdown of 18 affords olefin 13, trimethylphosphite, and carbon dioxide. It is also possible that ylide 18 is generated directly via nucleophilic attack on carbene 12 by phosphite. Evidence for an ylide intermediate has been obtained from trapping experiments with trithiocarbonates and benzaldehyde.3... 

The alkyl thiocarbonates are derived from dithiocar-bonic acid, HO.CS.SH, or trithiocarbonic acid, HS.CS.SH. Carbon disulphide reacts with sulphides to form salts analogous to the carbonates, which are formed by the union of carbon dioxide and metallic oxides —... 

Titanium complexes have been shown to be active for the synthesis of cyclic carbonates or either di- or trithiocarbonates from epoxides and either carbon dioxide or carbon disulfide (Scheme 5.6). Titanium-catalysed synthesis of cyclic carbonates has been recently reviewed by North and coworkers. Titanium-salen complexes find application as catalysts, in combination with tetrabutylammonium bromide or tributylamine, for the synthesis of di- or trithiocarbonates from epoxides and carbon disulfide. It is worth highlighting that the catalyst loading can be reduced to 0.5 mol%, although 1 mol% of catalyst was required in order to achieve quantitative yields. The catalyst system showed a preference for dithiocarbonate formation for most of the epoxides studied. 

Anhydrous Na-benzenesulfinate added in small portions at 0 during 1 hr. to a stirred soln. of methyl dithiochloroformate in dimethylformamide, and stirring continued 4 hrs. at the same temp. S -methyl S-phenyl trithiocarbonate S,S-dioxide. Y 61%. F. e. and procedure s. N.H. Nilsson and A. Senning, B. 107, 2345 (1974). 

Trithiocarbonate 55 -dioxides ArS02CSaAr undergo [4 + 2] cycloaddition with 1,3-dienes to afford the unstable A -dihydrothiopyrans (1), which readily lose ArSOaH to give the corresponding 2J -thiopyrans. Addition of ArSOaH to these 2/f-thiopyrans gives the 4-arylsulphinyl-2-arylthio-A -dihydrothiopyrans isomeric with (1). Evidence for the existence of the unstable 4-thioxotetrahydro-furan-3-ones was obtained by trapping them with 2,3-dimethylbuta-l,3-diene, which yielded the spiro-compounds (2) these underwent unusual mass spectral... 

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