S-((phenylsulfonyl)difluoromethyl)thiophenium salts: carbon-selective electrophilic difluoromethylation of ß-ketoesters, ß-diketones, and dicyanoalkylidenes.
Angew Chem Int Ed Engl
; 53(7): 1827-31, 2014 Feb 10.
Article
em En
| MEDLINE
| ID: mdl-24505003
ABSTRACT
S-((Phenylsulfonyl)difluoromethyl)thiophenium salts were designed and prepared by a triflic acid catalyzed intramolecular cyclization of ortho-ethynyl aryldifluoromethyl sulfanes. The thiophenium salts were found to be efficient as electrophilic difluoromehtylating reagents for introduction of a CF2 H group to sp(3) -hybridized carbon nucleophiles such as of ß-ketoesters and dicyanoalkylidenes. The (phenylsulfonyl)difluoromethyl group can be readily transformed into CF2 H under mild reaction conditions. Enantioselective electrophilic difluoromethylation was also achieved in the presence of bis(cinchona) alkaloids.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tiofenos
/
Cetonas
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article