61153-49-9Relevant academic research and scientific papers
A Carbene Strategy for Progressive (Deutero)Hydrodefluorination of Fluoroalkyl Ketones
Bi, Xihe,Sivaguru, Paramasivam,Song, Qingmin,Wang, Zikun,Zanoni, Giuseppe,Zhang, Xiaolong,Zhang, Xinyu
, (2021/12/23)
Hydrodefluorination is one of the most promising chemical strategies to degrade perfluorochemicals into partially fluorinated compounds. However, controlled progressive hydrodefluorination remains a significant challenge, owing to the decrease in the stre
Direct Synthesis of Tri-/Difluoromethyl Ketones from Carboxylic Acids by Cross-Coupling with Acyloxyphosphonium Ions
Ispizua-Rodriguez, Xanath,Munoz, Socrates B.,Krishnamurti, Vinayak,Mathew, Thomas,Prakash
supporting information, p. 15908 - 15913 (2021/10/07)
A simple and straightforward approach to the synthesis of trifluoromethyl and difluoromethyl ketones from widely available carboxylic acids is disclosed. The transformation utilizes an acyloxyphosphonium ion as the active electrophile, conveniently generated in situ from the carboxylic acid substrate by using commodity chemicals. The utility of the reaction system is exemplified by its chemoselectivity, with tolerance to a variety of important functional groups. The late-stage functionalization of carboxylic acid active pharmaceutical ingredients and pharmaceutically relevant compounds is also discussed.
Difluoromethylation of carboxylic acids via the addition of difluorinated phosphorus ylide to acyl chlorides
Trifonov, Alexey L.,Levin, Vitalij V.,Struchkova, Marina I.,Dilman, Alexander D.
, p. 5304 - 5307 (2017/11/06)
A one-step protocol for the difluoromethylation of carboxylic acids is described. The reaction involves the interaction of intermediate acyl chlorides with in situ generated difluorinated phosphorus ylide Ph3P=CF2. Aromatic acids can be selectively transformed within one step either to bis-difluoromethylated alcohols or to difluorinated ketones depending on the particular reaction conditions. For bulky α-branched carboxylic acids, only ketones are produced.
The reduction of α-silyloxy ketones using phenyldimethylsilyllithium
Fleming, Ian,Roberts, Richard S.,Smith, Stephen C.
, p. 1215 - 1228 (2007/10/03)
Phenyldimethylsilyllithium reacts with acyloin silyl ethers RCH(OSiMe3)COR 8 to give regiodefined silyl enol ethers RCH=C(OSiMe2Ph)R 9, and hence by hydrolysis ketones RCH2COR 10. The yields can be high but are usually moderate. The mechanism of this reduction is established to involve a Brook rearrangement (Scheme 6) rather than a Peterson elimination (Scheme 1). Although the mechanism appears to be the same in each case, the stereochemistries of the silyl enol ethers 9 are opposite in sense in the aromatic series (R = Ph, Scheme 7) and the aliphatic series (R = cyclohexyl, Scheme 8), with the major aromatic silyl enol ether being the thermodynamically less stable isomer E-PhCH=C(OSiMe2Ph)Ph E-9aa, and the major aliphatic silyl enol ether being the thermodynamically more stable isomer Z-c-C6H11CH= C(OSiMe2Ph)-c-C6H11 Z-9ba. This is a consequence of anomalous anti-Felkin attack in the aromatic series. The reaction with the silyl ether ButCH(OSiMe3)COPh 13b is normal in giving Z-ButCH= C(OSiMe2Ph)Ph Z-38 (Scheme 11), but reduction of the silyl ether 8a with lithium aluminium hydride is also anti-Felkin giving with high selectivity the meso diol PhCH(OH)CH(OH)Ph 39. The reaction between Phenyldimethylsilyllithium and the acyloin silyl ether 8d (R = But) does not give the ketone ButCH2COBut, but gives instead the anti-Felkin meso diol ButCHOHCHOHBut 40 also with high selectivity (Scheme 12). Silyllithium and some related reagents react with trifluoromethyl ketones 46 and 48 to give α,α-difluoro silyl enol ethers 47 and 49 (Scheme 14).
A convenient preparative method for α-trifluoromethyl amines
Watanabe, Shoji,Fujita, Tsutomu,Sakamoto, Masami,Hamano, Hiroyuki,Kitazume, Tomoya,Yamazaki, Takashi
, p. 15 - 19 (2007/10/03)
α-Trifluoromethyl amines (IV) were prepared in three steps: preparation of α-trifluoromethyl ketones (I), their conversion to benzyloximes (II), and reduction of the oximes (II) with lithium aluminium hydride and sodium methoxide. For example, α-trifluoromethyltridecylamine was obtained from the reduction of trifluoromethyl dodecyl ketone benzyl oxime. Elsevier Science S.A.
A microbially-based approach for the synthesis of chiral secondary alcohols bearing the difluoromethyl or chlorodifluoromethyl group
Kitazume, Tomoya,Asai, Masatomo,Tsukamoto, Takashi,Yamazaki, Takashi
, p. 271 - 284 (2007/10/02)
A synthetic approach to both enantiomers of the secondary alcohols , involving the stereoselective hydrolysis of ester derivatives, is described.The absolute configurations of these difluoromethylated or chlorodifluoromethylated molecules were determined.
