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Thiols from alkenes

Also via Section 44 (Alcohols and Thiols from Alkenes). [Pg.225]

DzhemUev, N tekhimiya, 1979, 19,425 [thiols from alkenes, using HjS plus EtAlCljl H. [Pg.10]

Ethyleneamines are used in certain petroleum refining operations as well. Eor example, an EDA solution of sodium 2-aminoethoxide is used to extract thiols from straight-mn petroleum distillates (314) a combination of substituted phenol and AEP are used as an antioxidant to control fouling during processing of a hydrocarbon (315) AEP is used to separate alkenes from thermally cracked petroleum products (316) and TEPA is used to separate carbon disulfide from a pyrolysis fraction from ethylene production (317). EDA and DETA are used in the preparation and reprocessing of certain... [Pg.48]

This reaction is based on a stoichiometric reaction of multifunctional olefins (enes) with thiols. The addition reaction can be initiated thermally, pho-tochemically, and by electron beam and radical or ionic mechanism. Thiyl radicals can be generated by the reaction of an excited carbonyl compound (usually in its triplet state) with a thiol or via radicals, such as benzoyl radicals from a type I photoinitiator, reacting with the thiol. The thiyl radicals add to olefins, and this is the basis of the polymerization process. The addition of a dithiol to a diolefin yields linear polymer, higher-functionality thiols and alkenes form cross-linked systems. [Pg.77]

Sulfides, or thioethers, are sulfur analogues of ethers, and like ethers they can be either symmetrical (R2S) or unsymmetrical (RSR1, where R and R are different). Sulfides can be prepared from alkyl halides by a Williamson-type synthesis with sodium hydrogen sulfide, sodium thiolate or sodium sulfide from alkyl or aryl halides via the Grignard reagent (11) from alkenes by radical-catalysed addition of thiols or by reduction of sulfoxides (Scheme 9).2b... [Pg.50]

The addition of thiols to alkenes is a free radical reaction that is catalysed by formation of phenyl radicals from the dibenzoyl peroxide catalyst (12), and in which the R S- radical can continue the radical chain reactions as shown in Scheme 10. In this reaction, the initial cleavage of dibenzoyl peroxide (12) is facilitated by the relatively weak peroxide ( 0-0 ) bond the subsequently formed alkylthio (R S-) free radical is an electrophilic species which... [Pg.50]

Examples of alkylation, dealkylation, homologation, isomerization, and transposition are given in Sections 1, 17, 33, and so on, lying close to a diagonal of the index. These sections correspond to such topics as the preparation of acetylenes from acetylenes carboxylic acids from carboxylic acids and alcohols, thiols, and phenols from alcohols, thiols, and phenols. Alkylations that involve conjugate additions across a double bond are given in Section 74E (Alkyls, Methylenes, and Aryls from Alkenes). [Pg.589]

Examples of name reactions may be found by first considering the nature of the starting material and product. The Wittig reaction, for instance, is given in Section 199 (Alkenes from Aldehydes) and in Section 207 (Alkenes from Ketones). The aldol condensation may be found in the chapters on difunctional compounds in Section 324 (Alcohol, Thiol-Aldehyde) and in Section 330 (Alcohol, Thiol-Ketone). Examples of the synthetically important alkene metathesis reaction are provided primarily in Section 209 (Alkenes from Alkenes). [Pg.589]

Alcohol, Thiol-Ketone). Examples of the synthetically important alkene metathesis reaction are mostly found in Section 209 (Alkenes from Alkenes). [Pg.816]

The asymmetric a-sulfenylation of ketones is a particularly challenging reaction, as demonstrated by the poor success reported in the stereoselective variants via classical enolate/azaenolate reaction with an electrophilic sulfur reagent [71]. An umpolung approach has been devised by Coltart and co-workers [72] to effect the first asymmetric a-sulfenylation of ketones with arene thiols. Nitroso alkene derivatives, in i/tM-generated under basic conditions from a-chloro oximes, reacted with arene thiols in the presence of cinchona thiourea 27, which promoted the conjugate addition of thiophenol (Scheme 14.25). The chiral nonracemic a-sulfenylated oximes were directly hydrolyzed by IBX to ketones in high yield and good enantioselectivity. [Pg.512]

In practice, the scope and limitations of this reaction are governed by the limitations of the S 2 reaction and by competition between substitution and jS-elimination (Section 9.8). The reaction is most useful for preparation of thiols from primary halides. Yields are lower from secondary halides because of the competing jS-elimination (E2) reaction. V Sth tertiary halides, jS-elimination (E2) predominates, and the alkene formed by dehydrohalogenation is the major product. [Pg.469]

Fig. 8.52 Selected examples from addition of thiolacetic acid and thiols to alkenes catalyzed by In(lll) salts. Fig. 8.52 Selected examples from addition of thiolacetic acid and thiols to alkenes catalyzed by In(lll) salts.
A good example of using the modular approach is the construction of gly-copolymers from alkene backbone-functional polymers via metal-free thiol-ene click reaction as reported by Stenzel and coworkers (Figure 8.7) [20]. This biologically friendly nature of thiol - ene click reaction is a powerful synthetic tool for preparing the biofunctional polymer and investigating bioprocesses. Another example can be found in the work of McCormick in which an attractive strategy... [Pg.258]

The main by-products of this synthesis type are sulfides and the isomer resulting from the Markownikoff addition to the alkene. For example, in the synthesis of 1-butanethiol (eq. 4), 5-thianonane, C H SC H, and 2-butanethiol are produced as by-products. The 2-butanethiol has uses as a herbicide intermediate and a gas odorant blend component and is further processed. The 5-thianonane is incinerated or reprocessed for fuel value. Sulfides account for up to 10% of the thiols produced. Another 2—5% is the Markownikoff addition product. [Pg.11]


See other pages where Thiols from alkenes is mentioned: [Pg.44]    [Pg.44]    [Pg.45]    [Pg.70]    [Pg.58]    [Pg.70]    [Pg.39]    [Pg.45]    [Pg.45]    [Pg.44]    [Pg.44]    [Pg.45]    [Pg.70]    [Pg.58]    [Pg.70]    [Pg.39]    [Pg.45]    [Pg.45]    [Pg.17]    [Pg.75]    [Pg.17]    [Pg.75]    [Pg.729]    [Pg.427]    [Pg.710]    [Pg.271]    [Pg.535]    [Pg.16]    [Pg.32]    [Pg.445]    [Pg.12]    [Pg.59]    [Pg.164]   
See also in sourсe #XX -- [ Pg.1689 ]




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From alkenes

From thiols

Sulfides from thiols + alkenes

Thiols alkenes

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