A novel synthetic route to ethyl 3-substituted-trans-2,3-difluoro-2-acrylates and their reactions with nucleophiles
作者:Qisheng Zhang、Long Lu
DOI:10.1016/s0040-4039(00)01517-3
日期:2000.10
Reaction of a variety of trans-1-trimethylsilyl-1,2-difluoroalkenes with ethyl chloroformate in the presence of potassium fluoride gave the corresponding ethyl 3-substituted-trans-2,3-difluoro-2-acrylates in good yields, which reacted with a variety of nucleophiles such as hydrazine hydrate, amidines and thiourea etc. in the presence of bases to afford the corresponding 4-fluoropyrazole, 5-fluoropyrimidine
HFC-134a as a fluorinated building block: short syntheses of α-fluoroenones
作者:J.Marie Bainbridge、Stuart Corr、Masatomi Kanai、Jonathan M Percy
DOI:10.1016/s0040-4039(99)02184-x
日期:2000.2
1,1,1,2-Tetrafluoroethane (HFC-134a) has been transformed into a range of alpha-fluoroenones via a direct route. Dehydrofluorinatisn/metallation allowed trifluorovinylsilanes to be prepared; these could be converted in situ, or isolated and treated further, with alkyllithium reagents to give difluorovinylsilanes. Fluoride-catalysed addition to aldehydes followed by acidic work-up allowed the isolation of a range of alpha-fluoroenones in two- or three-pots. (C) 2000 Elsevier Science Ltd. All rights reserved.