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Sulfur-carbon bonds cleavage

Thiirene dioxides readily react with an entire spectrum of enamines to provide novel acyclic and cyclic systems172. These products result mostly from carbon-carbon or carbon-sulfur bond cleavage in the intermediate fused thiirane dioxide 167 (equation 67). [Pg.427]

Several studies have been performed on the photodecomposition of diaryl sulfones and polysulfones Khodair, et. al., (21) demonstrated that the photodecomposition of diaryl sulfones proceeds by a free-radical mechanism with initial carbon-sulfur bond cleavage. This gives an aryl radical and an aromatic sulfonyl radical. The latter radical can react with oxygen and a hydrogen donor to eventually form the hydroxyl radical. The hydroxy radical may attack the aromatic nucleus in PET and forms the hydroxyterephthaloyl radical. [Pg.259]

Van Hamme, J. D. Fedorak, P. M. Foght, J. M., et al., Use of a novel fluorinated organosulfur compound to isolate bacteria capable of carbon-sulfur bond cleavage. Applied and Environmental, Microbiology,. 2004. 70(3) pp. 1487-1493. [Pg.224]

Photochemical, carbon-sulfur bond cleavage is also observed in compounds containing sulfur in oxidation states higher than that which exists in sulfides and in dialkyl dithioacetals. For example, the irradiation of the sulfoxide 47 in methanol produces109 a 58% yield of galacti-tol (52). Even though homolysis of the carbon-sulfur bond does occur in 47, it is unlikely that 52 results from a simple, carbon-sulfur bond-cleavage, as such a reaction predicts products that were not observed... [Pg.153]

Disulfides (RS-SRJ are not as useful as peroxides in their photochemical reactions, partly because carbon-sulfur bond cleavage (to give R" and RSi) competes more effectively with sulfur-sulfur bond cleavage than does C-O with 0-0 cleavage for peroxides, but largely because thiyl radicals are less reactive than their oxygen analogues. [Pg.162]

Thiiranes appear9 to undergo carbon-sulfur bond cleavage more readily, but this process is less well investigated. The only photoproduct so far obtained from methylthiirane (1) is the dimeric allyl... [Pg.5]

The photolysis of cyclic sulfones leads to carbon-sulfur bond cleavage and the extrusion of sulfur dioxide. In the diphenyl derivative (34 R = Ph), this is accompanied by the formation of a new carbon-carbon bond, and the product is ra w-l,2-diphenylbenzocyclobutene... [Pg.12]

The photochemistry of certain cyclic mercaptoles has been investigated,43 and the two major pathways can be interpreted in terms of initial carbon-sulfur bond cleavage [Eq. (11)]. [Pg.15]

The reduction of sulfones with Sml2 can result in deoxygenation, to give the parent sulfide,59 or carbon-sulfur bond cleavage, depending on the substrate and the reaction conditions employed.60 For example, alkyl and alkenyl phenyl sulfones are reductively cleaved by Sml2 in the presence of HMPA. In the reduction of alkenyl sulfones, competing reduction of the electron-deficient alkene is not observed (Scheme 4.50).60... [Pg.63]

The photolysis of dialkylphenacylsulfonium salts and dialkyl-4-hydroxyphenyl-sulfonium salts is different from that of triphenylsulfonium salts. The latter compounds undergo irreversible photoinduced carbon-sulfur bond cleavage the former compounds, however, react by reversible photodissociation and form resonance-stabilized ylids as shown in Fig. 5. Because of the slow thermally induced reverse reaction, only small equilibrium concentrations of the ylid and acid arc present during irradiation and the concentration will rapidly decrease when photolysis has been terminated. Therefore, in contrast to triarylsulfonium salt initiation, no dark reaction will continue after the irradiation step. [Pg.67]

Electrolytic desulfurization of o-aminobenzyl sulfide, sulfoxide or sulfone illustrates carbon-sulfur bond cleavage. Careful control of the reaction conditions is important to achieve chemoselectivity (Scheme 17). Trifluoromethyl substituents are not reduced under the conditions used (Cd sheet ca-... [Pg.976]

Electrochemical reduction of sulfonium salts has been the subject of a series of recent papers from Saeva et al. [52,63]. Reduction of sulfonium salts is again irreversible, resulting in carbon-sulfur bond cleavage [64], The reduction potentials are sensitive to the electronegativity of the fragmenting radical (Table 1) [52], Naphthylmethylsulfonium salts of the same series exhibit the same trend [52]. Saeva considered two-step and single step (concerted) reductive cleavage mechanisms, as shown in Scheme 2. [Pg.322]

However, unlike the triaryIsulfonium salts, these compounds undergo reversible photoinduced ylid formation rather than homolytic carbon-sulfur bond cleavage. Because the rate of the thermal back reaction is appreciable at room temperature, only those monomers that are more nucleophilic than the ylid will polymerize. Epoxides, vinyl ethers, and cyclic acetals undergo facile cationic polymerization when irradiated in the presence of dialkylphenacylsulfonium salts as photoinitiators. [Pg.104]

Carbon-Sulfur Bond Cleavage The Thienium Cation Diels-Alder Reaction... [Pg.226]


See other pages where Sulfur-carbon bonds cleavage is mentioned: [Pg.166]    [Pg.1076]    [Pg.1098]    [Pg.1076]    [Pg.1098]    [Pg.65]    [Pg.156]    [Pg.89]    [Pg.647]    [Pg.663]    [Pg.166]    [Pg.166]    [Pg.308]    [Pg.199]    [Pg.197]    [Pg.8]    [Pg.511]    [Pg.111]    [Pg.7]    [Pg.423]    [Pg.308]    [Pg.166]    [Pg.98]    [Pg.294]    [Pg.295]    [Pg.10]    [Pg.265]    [Pg.137]    [Pg.144]   
See also in sourсe #XX -- [ Pg.663 , Pg.664 , Pg.972 , Pg.973 , Pg.974 , Pg.975 , Pg.976 , Pg.977 ]

See also in sourсe #XX -- [ Pg.444 ]

See also in sourсe #XX -- [ Pg.224 , Pg.745 , Pg.769 , Pg.772 ]

See also in sourсe #XX -- [ Pg.150 ]

See also in sourсe #XX -- [ Pg.15 , Pg.31 ]




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Carbon cleavage

Carbon sulfur

Carbon-sulfur bond

Carbon-sulfur bond cleavage reactions

Carbonates cleavage

Dithioacetals carbon-sulfur bond cleavage

Sulfides oxidative carbon-sulfur bond cleavage

Sulfur bonding

Sulfur bonds

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