Direct transformations of ketones to gamma-unsaturated thiols via [2,3]-sigmatropic rearrangement of allyl sulfinyl carbanions: A combined experimental and computational study

Citation
Aa. Fokin et al., Direct transformations of ketones to gamma-unsaturated thiols via [2,3]-sigmatropic rearrangement of allyl sulfinyl carbanions: A combined experimental and computational study, J ORG CHEM, 65(10), 2000, pp. 2984-2995
Citations number
86
Categorie Soggetti
Chemistry & Analysis","Organic Chemistry/Polymer Science
Journal title
JOURNAL OF ORGANIC CHEMISTRY
ISSN journal
00223263 → ACNP
Volume
65
Issue
10
Year of publication
2000
Pages
2984 - 2995
Database
ISI
SICI code
0022-3263(20000519)65:10<2984:DTOKTG>2.0.ZU;2-K
Abstract
The reaction of a series of ketones with dimsylsodium in dimethyl sulfoxide resulting in the formation of gamma-unsaturated thiols was studied experim entally. [2,3]-Sigmatropic rearrangements of beta-unsaturated sulfinyl carb anions are involved at the key step of those transformations. DFT computati ons at the B3LYP/6-31+G* level indicated that such rearrangements, as well as some typical [2,3]-sigmatropic rearrangements, e.g., thermal rearrangeme nts of allyl sulfoxides and Wittig rearrangements of sulfur ylides and lith iated allyloxy methyl anions, are concerted and moderately synchronous proc esses. Negative (diatropic) nucleus-independent chemical shifts (NICS) and high diamagnetic susceptibility exaltations indicate that the transition st ructures of these [2,3]-sigmatropic migrations are aromatic.