199854-32-5Relevant academic research and scientific papers
SYNTHESIS OF DIFLUOROMETHYL ETHERS AND SULFIDES
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Paragraph 0076-0078, (2014/07/22)
The synthesis of difluoromethyl ethers and sulfides with a simple, non-ozone- depleting reagent is described. The difluoromethylation of phenols with this reagent occurs at room temperature within minutes with exceptional functional group tolerance. The mild conditions makes possible tandem processes for the conversion of aryl boronic acids, aryl halides and arenes to difluoromethyl ethers. Mechanistic studies support a reaction pathway involving nucleophilic attack of the phenolate to difluorocarbene.
Deoxygenative gem-difluoroolefination of carbonyl compounds with (chlorodifluoromethyl)trimethylsilane and triphenylphosphine
Wang, Fei,Li, Lingchun,Ni, Chuanfa,Hu, Jinbo
supporting information, p. 344 - 351 (2014/03/21)
Background: 1,1-Difluoroalkenes cannot only be used as valuable precursors for organic synthesis, but also act as bioisosteres for enzyme inhibitors. Among various methods for their preparation, the carbonyl olefination with difluoromethylene phosphonium ylide represents one of the most straightforward methods. Results: The combination of (chlorodifluoromethyl)trimethylsilane (TMSCF2Cl) and triphenylphosphine (PPh3) can be used for the synthesis of gem-difluoroolefins from carbonyl compounds. Comparative experiments demonstrate that TMSCF2Cl is superior to (bromodifluoromethyl)trimethylsilane (TMSCF2Br) and (trifluoromethyl)trimethylsilane (TMSCF3) in this reaction. Conclusion: Similar to many other Wittig-type gem-difluoroolefination reactions in the presence of PPh3, the reaction of TMSCF2Cl with aldehydes and activated ketones is effective.
Synthesis of gem-difluorocyclopropa(e)nes and O-, S-, N-, and P-difluoromethylated compounds with TMSCF2Br
Li, Lingchun,Wang, Fei,Ni, Chuanfa,Hu, Jinbo
supporting information, p. 12390 - 12394 (2013/12/04)
Two-in-one: Me3SiCF2Br is an efficient difluorocarbene source and is compatible with both neutral and aqueous basic conditions. Bromide-ion-initiated [2+1] cycloaddition with alkenes/alkynes and hydroxide ion promoted α-addition with (thio)phenols, (thio)alcohols, sulfinates, heterocyclic amines, and H-phosphine oxides give the corresponding gem-difluorinated compounds with broad functional-group tolerance. Copyright
Chlorodifluoromethyl aryl ketones and sulfones as difluorocarbene reagents: The substituent effect
Wang, Fei,Zhang, Laijun,Zheng, Ji,Hu, Jinbo
experimental part, p. 521 - 528 (2011/08/22)
We have investigated the different chlorodifluoromethyl aryl ketones 1a-1g and sulfones 2a-2h as difluorocarbene reagents for O- and N- difluoromethylations. It was found that the sulfone reagents 2 were generally more efficient in difluoromethylation than the ketone reagents 1. Furthermore, while the different substituents on ketone reagents 1 did not show a remarkable impact on the difluoromethylation reaction, the substituent effect on the sulfone reagents 2 was much more significant. Finally, we found that p-chlorophenyl chlorodifluoromethyl sulfone 2d and p-nitrophenyl chlorodifluoromethyl sulfone 2h were among the most powerful difluorocarbene reagents in this category for O-difluoromethylations.
Chloride ion-catalyzed generation of difluorocarbene for efficient preparation of gem-difluorinated cyclopropenes and cyclopropanes
Wang, Fei,Zhang, Wei,Zhu, Jieming,Li, Huaifeng,Huang, Kuo-Wei,Hu, Jinbo
supporting information; experimental part, p. 2411 - 2413 (2011/04/15)
A chloride ion-catalyzed generation of difluorocarbene from a relatively non-toxic and inexpensive precursor, Me3SiCF2Cl (1), under mild and neutral conditions leads to an efficient preparation of gem-difluorocyclopropenes and difluorocyclopropanes through [2 + 1] cycloaddition reactions with alkynes and alkenes, respectively.
