It has been found that potassium dihydrogen trifluoride is an efficient and easy-to-handle solid reagent for the ring-opening reaction of epoxides giving fluorohydrins regio- and stereo-selectively. The reaction proceeds via cis-addition of HF to the epoxide.
Enantioselective alpha-fluorination of aldehydes using chiral organic catalysts
申请人:MacMillan W.C. David
公开号:US20060189830A1
公开(公告)日:2006-08-24
Nonmetallic, chiral organic catalysts are used to catalyze enantioselective fluorination of enolizable aldehydes. Reaction systems composed of an enolizable aldehyde, an electrophilic fluorination reagent, and a nonmetallic chiral catalyst in the form of an imidazolidinone salt are also provided.
Tetrabutylammonium dihydrogentrifluoride: an efficient catalyst for regio and stereoselective conversion of epoxides to fluorohydrins under solid-liquid phase-transfer catalysis conditions.
作者:Dario Landini、Michele Penso
DOI:10.1016/s0040-4039(00)97281-2
日期:1990.1
Tetrabutylammonium dihydrogentrifluoride is an efficient and easy-to-handle hydrofluorinating agent in the ring-opening reaction of oxiranes to give good or excellent yields of fluorohydrins under solid-liquidPTCconditions.
Effective FluorinationReaction with Et<sub>3</sub>N˙3HF Under Microwave Irradiation
作者:Shoji Hara、Tomotake Inagaki、Tsuyoshi Fukuhara
DOI:10.1055/s-2003-39395
日期:——
Fluorination reaction of epoxides and alkyl mesylates can be effectively achieved by reaction with Et3NË3HF under microwave irradiation. The reaction time could be greatly reduced compared to the reaction under thermal conditions. The reactions were completed in a few minutes and the use of large excess of reagents could be avoided.
The ring-opening reaction of aliphatic epoxides with potassium fluoride-poly (hydrogen fluoride) is enhanced by a catalytic amount of triphenylphosphine. It is assumed that phosphonium fluoride species formed from triphenylphosphine work as fluorinating agents in this reaction.