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Sulphides vinyl

Vinyl sulphide, CH = CH S, has been identified in the oil of Allium ursinum. It is an evil-smelling liquid of specific gravity 0 912. It boils at 101°. [Pg.293]

Van t Hoff t-factors 565 Vinylallenes rearrangement of 748 synthesis of 737 Vinyl carbonium ions 620 17a-Vinyl-17/f-hydroxysteroids, epimerization of 735 Vinyl sulphides, as alkyl sulphoxide reduction products 930, 932 Vinyl sulphones - see also Alkenyl... [Pg.1210]

This series of reagents is characterized by the use of metals under the appropriate conditions. In this regard, a mixture of zinc dust and titanium tetrachloride in ether provided a useful synthesis of vinyl sulphides, with the possibility of further substitution alpha to the sulphur atom, as outlined in equation (16). The reaction is easy to carry out and gave yields of 49 to 87%, although the authors do not provide much detail of their experimental procedure and of the purity (chemical or stereochemical) of their products. [Pg.932]

As one might expect, the mesomeric effect of an alkoxy group enhances the activity of the C=C to attack by the carbene, but it has been noted that, where there is competition between an alkoxyvinyl group and an inactivated alkene group within the same molecule, an alkyl or aryl group stabilizes the transition state better than does the vinyloxy group (Scheme 7.10) [56]. It is noteworthy that vinyl sulphides are five times more reactive than are the enol ethers [62]. [Pg.326]

The second competing fragmentation reaction can be avoided by using a vinyl sulphide substrate 34. Vinyl sulphides have a lower oxidation potential compared... [Pg.45]

The technique has been developed to include the fluorination of vinyl sulphides to give vicinal difluorides in good yields [8]. [Pg.201]

Aliphatic thioketones result tautomerically pure from the reaction of H2S with ketals in the presence of ZnCl2. Deprotonation with LDA gives the enethiolate which can be silylated to form the silyl vinyl sulphide. These are fairly stable to traces of water but react with MeOH to give the enethiol (equation 3)7. [Pg.1870]

Experimental and theoretical studies of the gas-phase protonation of vinyl ethers, vinyl sulphides and vinyl selenides show, in conflict with the previous studies, that SMe and... [Pg.1142]

In some cases, however, a high degree of stereoselectivity could be obtained even with pure triplet excited carbonyl compounds. In these cases, e.g., the photocycloaddition of benzophenone to several methyl vinyl sulphides 113, the intermediary triplet 1,4-biradical preferentially undergoes one of two possible cyclization modes after intersystem crossing (Sch. 34) [60]. [Pg.113]

The reaction of sulphides with (dichloroiodo)benzene can lead to several kinds of products depending on the substrate and the reaction conditions [19]. Sulphides of great structural diversity (aliphatic, aromatic, heterocyclic) were oxidized efficiently by (dichloroiodo)benzene (one equivalent) in aqueous pyridine. The reaction was almost instantaneous and not noticeably sensitive to steric or electronic effects. Ethylenic double bonds were not attacked under these conditions however, in vinylic sulphides containing an electron-withdrawing group (COOH or RSO) ft- to the sulphur atom the oxidation was accompanied by nucleophilic attack to the double bond resulting in a mixture of products. The method is suitable for the preparation of I80-labelled sulphoxides using small quantities of H2,80. [Pg.102]

Krief and coworkers have also shown that vinyl sulphides are useful traps for the intramolecular carbolithiation reactions. Interestingly, as the sulphide substituent can be reductively removed, the cyclization reactions of benzyllithiums derived from 73 and 75 are synthetically equivalents to cyclizations onto disubstituted double bonds, giving rise by complementary routes to compound 74 (Scheme 20)46. Like the corresponding carbolithiation reactions onto monosubstituted alkenes they are highly stereoselective but dependent on the solvent used, i.e. the derivatives in which the methyl- and the phenylthio groups are cis (THF) or trans (pentane) one to the other are selectively formed. [Pg.312]

There is evidence that atom A in scheme (76) could be carbon. Phenyl migration has been postulated to account for skeletal rearrangement in phenyl vinyl sulphides (90) initial migration through the four-centre... [Pg.217]

The following monomers have been classified as donors styrene [78, 79], vinyl ethers and vinyl sulphides [78], vinyl acetate [80] vinylcarbazole [81, aziridine [82], 2-oxazoline [83], 2-benzyliminotetrahydrofuran [84], five-and six-membered cyclic iminoethers, cyclic amines, cyclic phospholanes and Schifif bases [85]. Trialkoxyethylenes [86]... [Pg.43]

Fig. 2. Reactivity of monomers with n-n conjugation (a) with styrene macroradical and (b) with methacrylate macroradical. O, Ethyl vinyl sulphide JV-vinylcarbazole , methyl vinyl sulphide. Fig. 2. Reactivity of monomers with n-n conjugation (a) with styrene macroradical and (b) with methacrylate macroradical. O, Ethyl vinyl sulphide JV-vinylcarbazole , methyl vinyl sulphide.
CH3)3CO— is an initiator residue]. With copolymerization of free monomers, they should have observed an increasing A/B ratio according to the method used with complex propagation, A/B should remain constant. The authors observed both cases. They concluded that maleic anhydride with a monomeric donor, like styrene, yields a DA complex by a reversible reaction, with an equilibrium constant of 10-1 to 10-2 dm3 mol-1. The initiating radical is formed from the complex, and the copolymerization is in fact a terpolymerization involving the two free monomers and their complex. These authors have applied the same technique in a study of the type of radicals formed in copolymerization of maleic anhydride with vinyl sulphides. Even in this case they provided evidence of the existence of a complex. [Pg.67]

We have not commented on the criteria determining the actual polymerisability of a monomer by cationic initiation, since they are well known The present review deals with monomers belonging to the n-donor (olefins, dienes, vinyl aromatics) and n-and n-donor (vinyl ethers, vinyl amines, vinyl sulphides) families, but not with purely n-donor and 6-donor monomers. [Pg.5]

Photo-oxidation of olefins in pyridine solution in the presence of FeCIs has been found to take one of three courses, depending on the substitution pattern of the substrate olefin. These routes lead to formation of a-chloroketones, gem-dichloroketones, and a,-dichloroketones, and have all been illustrated by their use in actual syntheses. a-Chloroketones have also been produced by irradiation of pyridine solutions of vinylsUanes or vinyl sulphides under similar conditions. DCA-sensitized photo-oxidation of l,2-diphenyl-3,3,4,4-tetramethylcyclobutene in MeCN leads to the corresponding ozonide in a process which occurs by initial formation of an oxirane. Jasmine lactone (12 ... [Pg.378]

Divinyl sulphide is also formed by the abstraction of two molecules of water from one of thiodiglycol. On treatment with gaseous hydrochloric acid, it forms aa dichloroethyl sulphide, a colourless liquid with a penetrating odour, which boils at 58 5° C. at 15 mm. mercury and has a density of 1-1972 at 15° C. On treatment of divinyl sulphide in aqueous solution with hydriodic acid, 8/3 diiodoethyl sulphide is formed (see p. 244). With chlorine various chlorinated compounds are formed, for instance, a/3 dichloroethyl vinyl sulphide ... [Pg.237]

The photoaddition of benzophenone to the vinyl sulphides (54) affords a mixture of the oxetanes (55) in yields ranging from 12 - 79X dependent on the alkene used. - Photoaddition of aldehydes to 2,3-dihydrofurans has been studied. The addition affords oxetanes of the type shown by (56) where addition of benzaldehyde affords two isomers. Addition to the furan derivative (57) was also studied. In this instance the addit ion of aldehydes afforded two types of oxetane illustrated by (58) and (59). ... [Pg.162]

Other miscellaneous additions reported include the photoaddition of thiocarboxylic acid to 3,4-diallyl-1,6-propano-1H,6H-3a-thia (S )-1,3,4,6-tetraazapentalene-2,5(3H,4H)-dithione, the Paterno-BUchi addition of methyl vinyl sulphides to benzophen-... [Pg.397]


See other pages where Sulphides vinyl is mentioned: [Pg.293]    [Pg.930]    [Pg.95]    [Pg.930]    [Pg.326]    [Pg.45]    [Pg.539]    [Pg.240]    [Pg.303]    [Pg.329]    [Pg.53]    [Pg.1364]    [Pg.5]    [Pg.463]    [Pg.12]   
See also in sourсe #XX -- [ Pg.293 ]

See also in sourсe #XX -- [ Pg.43 , Pg.67 ]

See also in sourсe #XX -- [ Pg.43 , Pg.67 ]




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Allyl vinyl sulphide

Allyl vinyl sulphide rearrangement

Ethyl vinyl sulphide

Methyl vinyl sulphide

Preparation of Vinyl Sulphides

Properties of Vinyl and Allyl Sulphides

Sulphides phenyl vinyl

Vinyl sulphide oxidation

Vinyl sulphides, reactions with

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