Trithiocarbonate 5-oxides

Organolithiums have been shown to add to a variety of trithiocarbonate oxides exclusively in a thiophilic maimer, as a consequence of the electrophilic character of the sulfine sulfur, to give an intermediate carbanion stabilized by three sulfur atoms the soft carbanion, which forms trithioorthoester oxide on quenching with water, acts as the equivalent of the (alkylthio)carbonyl anion in Michael addition.98... 

Trithiocarbonate oxides. These species (sulfines) are obtained on treatment of dialkyl trithiocarbonates with MCPBA at 0°. They react with organometallic reagents to provide bis(alkylthio)methyl sulfoxides. 

Similarly, carbon disulfide and propylene oxide reactions are cataly2ed by magnesium oxide to yield episulftdes (54), and by derivatives of diethyUiac to yield low molecular weight copolymers (55). Use of tertiary amines as catalysts under pressure produces propylene trithiocarbonate (56). 

Carbon disulfide reacts with ethylene oxide to give ethylene trithiocarbonate (90), and isocyanates yield derivatives of 2-oxazohdinone (91). 

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. 

Under similar conditions, perfluoroalkyl iodides react with alkyl phosphates to give fluorinated phosphine oxides, phosphinates, and phosphines [54 (equation 49) The product formed depends upon the stoichiometry and type of iodide used. When sodium alkyl trithiocarbonates are used as substrates, perfluoroalkyl tri-thiocarbonates ate formed [55]. 

A wide variety of sulfines has been produced by the oxidation reaction with mCPBA starting from dithioesters [104, 105], trithioperesters [106], heterocyclic C=S compounds [107], thionoesters [108] (see also [109]), dit-hiocarbonates [110] and trithiocarbonates [111]). 

Trithiocarbonate S-oxides are reactive towards alkyllithiums [111] thio-philic additions were carried out at -78 °C. The resulting carbanions, stabilised by three sulfur groups, were quenched by water or by other electrophiles to afford trithioorthoester oxides. With enones, 1,4-addition was observed elimination of an alkanesulfenic acid led to /1-oxoketenedithioace-tals which could be transformed into 4-oxoalkanethioates. This Umpolung route allows the formal use of an (alkylthio)carbonyl anion. 

The l,3-dithiolane-2-thione (326) was first prepared by the reaction of ethylene dibromide with sodium trithiocarbonate in ethanol (1862LA(123)83>. Presumably the best synthesis of (326) is the reaction of ethylene oxide with carbon disulfide and potassium hydroxide in methanol at room temperature (46JCS1050). 

The first example of an enzymatic cleavage of trithiocarbonate 127 followed by oxidative dimerization was reported to give an inseparable mixture of 1,2,5,6-tetrathiocines 128 and 129 (Equation 40) <2002TL2589>, whose structure assignments were based on mass spectrometry data. 

The controlled emulsion polymerization of styrene using nitroxide-mediated polymerization (NMP), reversible addition-fragmentation transfer polymerization (RAFT), stable free radical polymerization (SFR), and atom transfer radical polymerization (ATRP) methods is described. The chain transfer agent associated with each process was phenyl-t-butylnitrone, nitric oxide, dibenzyl trithiocarbonate, 1,1-diphenylethylene, and ethyl 2-bromo-isobutyrate, respectively. Polydispersities between 1.17 and 1.80 were observed. 

Electrochemical reduction of CS2 in either DMF or MeCN yields the trithiocarbonate (16) and the 4,5-dimercapto-l,3-dithiole-2-thione (17) dianions, which on oxidation by iodine give the binary carbon sulfide C3S6 in good yields (equations 111 and 112). ... 

Cyclic trithiocarbonates undergo oxidative addition with the complex [Pt(PPhj)4], resulting, by the cleavage of a C—S bond, in the unusual heterometallacyclic compounds with structure 18 ( = 2, 3) (43). 

Several types of compounds containing the thiocarbonyl group, like trithiocarbonates [219], thioketones [219], and thioureas [219-221], undergo anodic oxidation to afford stable dimeric dications with a disulfide linkage ... 

These dimeric cations are reactive species and frequently, under preparative oxidation conditions, different products are obtained. Cyclic trithiocarbonates, for example, in moist acetonitrile can eliminate sulfur and react with water, yielding the corresponding carbonyl compound [222] ... 

The controlled oxidation using a peroxycarboxylic acid of trithiocarbonates (78) without a-hydrogens, and which therefore cannot form enethiols, yields the corresponding sulfines (79) (see p. 129). The use of other oxidants, e.g. concentrated nitric acid or an excess of the peroxycarboxylic acid, gives higher oxidation products like (80) and (81) (Scheme 42). 

The unidentate-bidentate equilibrium does not appear to occur in solutions of Cp2VS2CNEt2 obtained from CP2VCI and NaS2CNEt2- Both the trithiocarbonates and dithiocarbamate are oxidized to the corresponding cations by I2. The oxidative cleavage method for the preparation of vanadocene thioethers CP2VSR has been patented (see Vol. 5,p. 42). ... 

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