- 著者
- Fuchibe Kohei Koseki Yuta Aono Tatsuya Sasagawa Hisashi Ichikawa Junji
- 出版者
- Elsevier B.V.
- 雑誌
- Journal of fluorine chemistry (ISSN:00221139)
- 巻号頁・発行日
- vol.133, pp.52-60, 2012-01
- 被引用文献数
- 34 11
Controlled generation of difluorocarbene was effected by an NHC catalyst under mild conditions starting from trimethylsilyl 2,2-difluoro-2-fluorosulfonylacetate (TFDA). Cyclohexenones and tetralones were treated with TFDA in the presence of catalytic amounts of N,N′-dimesitylimidazolium chloride and sodium carbonate. The ketones were difluoromethylated with the generated difluorocarbene to afford enol difluoromethyl ethers without difluorocyclopropanation. The ethers thus obtained were dehydrogenated with DDQ to furnish aryl difluoromethyl ethers in high yield. Under similar conditions, secondary amides underwent difluoromethylation selectively on the oxygen atom to give difluoromethyl imidates, which allows the formation of 2-difluoromethoxypyridines.
- 著者
- Oh Ken Fuchibe Kohei Yokota Misaki Ichikawa Junji
- 出版者
- Georg Thieme Verlag
- 雑誌
- Synthesis (ISSN:00397881)
- 巻号頁・発行日
- vol.2012, no.6, pp.857-861, 2012-03
- 被引用文献数
- 16
Two methods for the difluorovinylidenation of carbonyl compounds have been developed to synthesize 1,1-difluoroallenes bearing various substituents. The reaction of 1-bromo-2,2-difluorovinyllithium, generated from 1,1-dibromo-2,2-difluoroethylene and n-butyllithium, with aldehydes or ketones, and subsequent acetylation, gives 2-bromo-3,3-difluoroallylic acetates. Elimination of these acetates with n-butyllithium affords 1,1-difluoroallenes in high yield. 3,3-Difluoro-2-iodoallylic acetates are similarly prepared from aldehydes or ketones on treatment with 2,2-difluoro-1-iodovinyllithium, generated from 1,1,1-trifluoro-2-iodoethane and lithium diisopropylamide, followed by acetylation. These acetates readily undergo elimination with zinc metal to afford 1,1-difluoroallenes in high yield.
1 0 0 0 OA A Facile Synthesis of 1,1-Difluoroallenes from Commercially Available 1,1,1-Trifluoro-2-iodoethane
- 著者
- Oh Ken Fuchibe Kohei Ichikawa Junji
- 出版者
- Georg Thieme Verlag
- 雑誌
- Synthesis (ISSN:00397881)
- 巻号頁・発行日
- vol.2011, no.6, pp.881-886, 2011-03
- 被引用文献数
- 2 5
1,1-Difluoroallenes are synthesized in good yield via zinc-promoted 1,2-elimination of 3,3-difluoro-2-iodoallylic acetates, which are prepared by the reaction of aldehydes or ketones with 1-iodo-2,2-difluorovinyllithium, generated from commercially available 1,1,1-trifluoro-2-iodoethane.Key words