Two-step conversion of carboxylic esters into distally fluorinated ketones via ring cleavage of cyclopropanol intermediates: application of sulfinate salts as fluoroalkylating reagents.
Org Biomol Chem
; 15(21): 4635-4643, 2017 May 31.
Article
in En
| MEDLINE
| ID: mdl-28513753
ABSTRACT
Tertiary cyclopropanols easily available from carboxylic esters have been used in the synthesis of distally fluorinated ketones. Cyclopropane ring cleavage reactions in methanol with aqueous tert-butyl hydroperoxide in the presence of a copper(ii) acetate catalyst and sodium triflinate (Langlois reagent) afford ß-trifluoromethyl ketones in 16-74% isolated yields. Sodium triflinate serves as a precursor of reactive trifluoromethyl copper species, enabling ring-opening trifluoromethylation, as evidenced by mechanistic studies. We also demonstrate here that other sulfinate salts, such as sodium 1,1-difluoroethanesulfinate, sodium 2-(4-bromophenyl)-1,1-difluoroethanesulfinate and sodium 1-(trifluoromethyl)cyclopropanesulfinate, can be used as fluoroalkylation reagents, resulting in the corresponding fluorinated ketones.
Full text:
1
Database:
MEDLINE
Language:
En
Journal:
Org Biomol Chem
Journal subject:
BIOQUIMICA
/
QUIMICA
Year:
2017
Type:
Article
Affiliation country:
Belarus