Sommelet-Hauser type

The mechanism of the indolization of aniline 5 with methylthio-2-propanone 6 is illustrated below. Aniline 5 reacts with f-BuOCl to provide A-chloroaniline 9. This chloroaniline 9 reacts with sulfide 6 to yield azasulfonium salt 10. Deprotonation of the carbon atom adjacent to the sulfur provides the ylide 11. Intramolecular attack of the nucleophilic portion of the ylide 11 in a Sommelet-Hauser type rearrangement produces 12. Proton transfer and re-aromatization leads to 13 after which intramolecular addition of the amine to the carbonyl function generates the carbinolamine 14. Dehydration of 14 by prototropic rearrangement eventually furnishes the indole 8. 

Otter et al. (89JHC1851) obtained the thienopyrimidine 253 in 50% yield by heating 5-(2-propynylthio)pyrimidine 248 in DMSO at 145°C. The reaction proceeds via a Claisen rearrangement of 248 in the allene 249, which then cyclizes to the product 253. An 18% yield of the thiomethyl compound 252 was also isolated. This was explained by a mechanism involving solvent incorporation into allene 249 to give intermediate 250 this intermediate then undergoes a Sommelet-Hauser type of rearrangement to afford 251, which cyclizes to the product 252. 

Triethylamine o-Methylthiomethylamines from ar. sulfilimines Sommelet-Hauser type rearrangement... 

A series of 3-arylthio-l,3-disubstituted-oxindoles were prepared by the reaction of a-diazocarbonyl compounds and sulfenamides involving a Rh-catalysed thia-Sommelet-Hauser-type rearrangement (Scheme 100). (g)... 

A different variant of this enzyme led to the dioxygenation of benzoic acid (36) to 1,2-diol 37, which served as the chiral starting material for Myers synthesis of the antibiotic (+)-doxycycline (46) (Scheme 15.7) [29]. Functional group manipulation of 37 led to epoxide 39, which was ligated with 40 to ketone 41. In a Sommelet-Hauser-type rearrangement... 

Reaction of benzyne with tertiary aliphatic amines to give anilines via Sommelet-Hauser and/or Stevens-type rearrangements of the intermediate ylid has been documented.362 363... 

Lactams participate in a number of ring enlargement reactions of different types. Because of the classification in this review they are described at other places too e.g. Sommelet-Hauser rearrangement (Chapter V3). 

Another type of ylidic rearrangement, the Sommelet-Hauser rearrangement, was discovered later, in 1937, by Sommelet and studied extensively by Sommelet and by Hauser. This transposition involves the base-promoted rearrangement of non stabilized ammonium and sulfonium ylides. Thus, the ammonium salt (11), when heated with alkali, gave cleanly the substituted diphenylmethane derivative (12 Scheme 5). Wittig found that the dibenzyl ammonium salt (13) reacted with phenyllithium giving two... 

Rearrangements of Sommelet type have been described for sulfonium salts by Hauser, Cantor, and Brasen.105 For example, sodamide converts S,S-dimethylbenzylsulfonium bromide in boiling ether into methyl 2-methylbenzyl sulfide ... 

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