- 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
- Kubota Tadahiko Ihara Masayuki Katayama Shinichi Nakai Hideki Ichikawa Junji
- 出版者
- Elsevier B.V.
- 雑誌
- Journal of power sources (ISSN:03787753)
- 巻号頁・発行日
- vol.207, pp.141-149, 2012-06
- 被引用文献数
- 20
Five 1,1-difluoro-1-alkenes bearing aryl groups are investigated as electrolyteadditives for high-charge-voltage lithiumionbatteries with an aim to induce favorable solid electrolyte interphase (SEI) formation. Among them, 1,1-difluoro-4-phenylbut-1-ene (DF-1) forms appropriate SEIs on the cathode and anode by its reactions under oxidative and reductive conditions, respectively, which was suggested by linear sweep and cyclic voltammetry. The SEIs formed with the DF-1 containing electrolyte on the cathode and anode were analyzed by X-ray photoelectron spectroscopy and time of flight-secondary ion mass spectrometry, indicating the following: (i) the cathode surface has a LiF-rich layer with unsaturated hydrocarbons, and (ii) the anode surface also has a LiF-rich layer, which probably includes fluoromethylene (CHF) compounds. The formation of the SEIs on both electrodes with DF-1 results in low impedance being maintained, and thus, particularly good cycle performance even at high-charge-voltage.
- 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