Alkylthioalkylation

Alkylsulfonylation (see Sulfonylation) Alkylthioalkylation Copper(II) chloride-Copper(II) oxide,... 

Friedel-Crafts type reactions of strongly deactivated arenes have been the subject of several recent studies indicating involvement of superelectrophilic intermediates. Numerous electrophilic aromatic substitution reactions only work with activated or electron-rich arenes, such as phenols, alkylated arenes, or aryl ethers.5 Since these reactions involve weak electrophiles, aromatic compounds such as benzene, chlorobenzene, or nitrobenzene, either do not react, or give only low yields of products. For example, electrophilic alkylthioalkylation generally works well only with phenolic substrates.6 This can be understood by considering the resonance stabilization of the involved thioalkylcarbenium ion and the delocalization of the electrophilic center (eq 4). With the use of excess Fewis acid, however, the electrophilic reactivity of the alkylthiocarbenium ion can be... 

Dimethyl sulfoxide (DMSO) can be used for carbon-carbon bond formation and as a precursor for the synthesis of stabilised sulfur ylides (see Chapter 3, p. 33). The sulfoxy S=0 group, like the sulfone (S02) group, has a stabilising effect on an adjacent carbanion hence, sulfinyl carbanions, like sulfonyl carbanions (see Chapter 10, p. 200), are useful reagents in organic synthesis. The carbanions (39) derived from alkylthioalkyl sulfoxides (38) are particularly valuable intermediates in syntheses (Scheme 21). 

Section E. a-Hydroxy-, a-Acyloxy-, and a-Alkylthioalkyl, Alkyl and Aryl Substituents... 

I.S.5 Phosphorothioates and phosphorodithioates containing alkylthioalkyl or arylthioalkyl groups... 

Bordwell and coworkers reported the stereospecific quantitative desulfurization of episulfides with organolithiums.39) The mechanism of this reaction, however, remained undefined. In addition to a disrotatory concerted sulfurane decomposition [i.e. Eq. 9), p elimination from a 2-alkylthioalkyl-lithium may be envisioned (see Eq. 10). However, independent stereo-... 

Bu Li at - 30 °C, followed by treatment with Mel. A diallyl sulphide behaves similarly in that one of the two S-substituents is lithiated, and this centre is the point at which the y-carbon of the other S-substituent is attached in the product. Compounds (67)—(69) are formed in approximately equal amounts by the photolysis of the /S-alkylthioalkyl-carbene derived from 3-crotyl-3-methylbutyrophenone tosylhydrazone sodium salt. An a-allylthioalkyl-carbene (70) behaves differently on irradiation at - 70 °C, giving an intermediate (71) which rearranges, without the need for irradiation, to give the violet thione (72) this last step is the first... 

On the other hand, 3-alkyl-li/-indoles react with NCS-dialkyl sulfides in the presence of base to give 3-alkyl-3-alkylthioalkyl-3//-indoles (indolinenes, eq 14). ... 

Relative to the arylthio derivatives, kinetic studies on homologous alkylthioalkyl halides have been largely ignored. It appears (see p. 51)... 

Synthesis of a-alkylthioalkyl sulphones by oxidation of dithioacetals with KMn04 has been reported." ... 

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