26902-68-1Relevant academic research and scientific papers
Synthesis of polyfluorinated ketones via ate-complexes
Pashkevich, K. I.,Khomutov, O. G.,Filyakova, V. I.,Kuchin, A. V.
, p. 1002 - 1003 (1994)
Asymmetric polyfluorinated ketones RFCOR are formed by treating various derivatives of (polyfluoro)alkanoic acids (esters, anhydrides, acid chlorides) with lithium tetraalkylaluminates ("ate-complexes").The highest yields of the ketones (65 - 78percent) were obtained from (polyfluoro)alkanoyl chlorides. - Key words: fluorinated ketones, synthesis; lithium tetraalkylaluminates, reaction with (polyfluoro)alkanoyl chlorides.
Stereoconvergent negishi arylations of racemic secondary alkyl electrophiles: Differentiating between a CF3 and an alkyl group
Liang, Yufan,Fu, Gregory C.
supporting information, p. 9523 - 9526 (2015/08/18)
In this report, we establish that a readily available nickel/bis(oxazoline) catalyst accomplishes a wide array of enantioconvergent cross-couplings of arylzinc reagents with CF3-substituted racemic secondary alkyl halides, a process that necessitates that the chiral catalyst be able to effectively distinguish between a CF3 and an alkyl group in order to provide good ee. We further demonstrate that this method can be applied without modification to the catalytic asymmetric synthesis of other families of fluorinated organic compounds.
A new, practical and efficient sulfone-mediated synthesis of trifluoromethyl ketones from alkyl and alkenyl bromides
Mu?oz, Lourdes,Rosa, Esmeralda,Bosch, Ma. Pilar,Guerrero, Angel
, p. 3311 - 3313 (2007/10/03)
We report herein a new and efficient method to prepare trifluoromethyl ketones from the corresponding bromides through sulfones in good yields.
Radical-mediated synthesis of trifluoroethyl amines and trifluoromethyl ketones from alkyl iodides
Kim, Sunggak,Kavali, Rajesh
, p. 7189 - 7191 (2007/10/03)
Radical reaction of alkyl iodides with trifluoromethyl phenylsulfonyl oxime ether 10 and hexamethylditin at 300 nm in benzene afforded the corresponding trifluoromethyl oxime ethers 11 in high yields, which were reduced into the 2,2,2-trifluoroethyl amines with lithium aluminium hydride. The trifluoroethyl amines could be converted into the corresponding trifluoromethyl ketones by treatment with NBS and DBU.
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.
Study on the effect of di- and trifluoromethyl groups on the Baeyer-Villiger reaction
Kitazume, Tomoya,Kataoka, Junichi
, p. 157 - 158 (2007/10/03)
Case studies of the Baeyer-Villiger reaction applied to di-and trifluoromethylketone derivatives and the effect of the fluoromethyl groups on the Baeyer-Villiger reaction, are described.
Efficient synthesis of optically pure 1,1,1-trifluoro-2-alkanols through lipase-catalyzed acylation in organic media
Hamada, Hiroki,Shiromoto, Mizuho,Funahashi, Makoto,Itoh, Toshiyuki,Nakamura, Kaoru
, p. 2332 - 2336 (2007/10/03)
Lipase-catalyzed esterification was successfully utilized for the optical resolution of 1,1,1-trifluoro-2-alkanol 1 when racemic 1 was treated with lipase from Candida antarctica in hexane in the presence of molecular sieves (4 A) to provide the corresponding (S)-acetate 2 in an optically pure state. Alkanol 1 is known as an important component of liquid crystal compounds which display remarkable ferroelectric liquid crystal (FLC) characteristics. Five types of optically pure alkanols, i.e., 1,1,1-trifluoro-2-octanol (1a), 1,1,1-trifluoro-2-nonanol (1b), 1,1,1-trifluoro-2-decanol (1c), 1,1,1-trifluoro-2-undecanol (1d), and 1,1,1-trifluoro-8-(benzyloxy)-2-octanol (1e), were thus obtained by the lipase-catalyzed acylation.
Chiral Synthesis Via Organoboranes. 38 Selective Reductions. 48. Asymmetric Reduction of Trifluoromethyl Ketones by B-Chlorodiisopinocampheylborane in High Enantiomeric Purity
Ramachandran, P. Veeraraghavan,Teodorovic, Aleksandar V.,Brown, Herbert C.
, p. 1725 - 1738 (2007/10/02)
(-)-B-Chlorodiisopinocampheylborane TM,1>, introduced by us several years ago, has been shown to reduce prochiral aryl and alkyl perfluorinated ketones to the corresponding optically active alcohols in very high ee.For example, 2,2,2-trifluoroacetophenone, trifluoroacetyl-1-naphthalene, and trifluoroacetyl-2-naphthalene are all reduced with 1 within 1-3 d at rt in 90percent ee, 78percent ee and 91percent ee, respectively.The optical purity of 1-phenyl-2,2,2-trifluoroethanol is upgraded to = 99percent ee by crystallizing the initially formed products from pentane. 1,1,2,2,2- pentafluoropropiophenone and 1,1,2,2,3,3,3-heptafluorobutyrophenone are reduced in 3 d with 1 to the corresponding alcohols in 92percent ee and 87 percent ee, respectively.The reagent reduces alkyl trifluoromethyl ketones at a rate faster than that of the aryl derivatives, while still providing the product alcohols in very high ee.Thus, 1,1,1-trifluoroacetone, 1,1,1-trifluorononan-2-one, and 1,1,1-trifluorodecan-2-one are all reduced within 4 - 8 h in 89percent ee, 92percent ee, and 91percent ee, respectively.Even α-sec-alkyl trifluoromethyl ketones are handled by 1 very efficiently.Thus cyclohexyl trifluoromethyl ketone is reduced by 1 at rt in 12 h to the product alcohol in 87percent ee.In all of these cases the trifluoromethyl group acts as the enantiocontrolling larger group as compared to the aryl or alkyl group.This produces alcohol products with stereochemistry opposite to those obtained for the corresponding hydrogen analogs.The steric and electronic influence of the trifluoromethyl group in achieving enantiocontrol in assymmetric reductions is discussed.Keywords: asymmetric reduction; trifluoromethyl ketones; DIP-Chloride; high enantiomeric purity
