- Radical Trifluoroacetylation of Alkenes Triggered by a Visible-Light-Promoted C–O Bond Fragmentation of Trifluoroacetic Anhydride
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We report a mild and operationally simple trifluoroacylation strategy of olefines, that utilizes trifluoroacetic anhydride as a low-cost and readily available reagent. This light-mediated process is fundamentally different from conventional methodologies and occurs through a trifluoroacyl radical mechanism promoted by a photocatalyst, which triggers a C?O bond fragmentation. Mechanistic studies (kinetic isotope effects, spectroelectrochemistry, optical spectroscopy, theoretical investigations) highlight the evidence of a fleeting CF3CO radical under photoredox conditions. The trifluoroacyl radical can be stabilized under CO atmosphere, delivering the trifluoroacetylation product with higher chemical efficiency. Furthermore, the method can be turned into a trifluoromethylation protocol by simply changing the reaction parameters. Beyond simple alkenes, this method allows for chemo- and regioselective functionalization of small-molecule drugs and common pharmacophores.
- Jeschke, Gunnar,Katayev, Dmitry,N?tel, Nicolas Yannick,Rombach, David,Zhang, Kun
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supporting information
p. 22487 - 22495
(2021/09/09)
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- An efficient route to 3-trifluoromethylpyrazole via cyclization/1,5-H shift and its applications in the synthesis of bioactive compounds
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A methodology for regioselective synthesis of 3-trifluoromethylpyrazole from the reaction of trifluoromethyl alkenone and tosylhydrazone has been developed. The reaction was proposed to proceed through a tandem cyclization and 1,5-H shift reaction, which can be applied to the synthesis of bioactive compounds like Celecoxib, Mavacoxib, and SC-560.
- Wang, Yongdong,Han, Jing,Chen, Jie,Cao, Weiguo
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p. 8256 - 8262
(2015/10/05)
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- A Weinreb amide approach to the synthesis of trifluoromethylketones
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A novel route to access trifluoromethylketones (TFMKs) from Weinreb amides is reported. This represents the first documented case of the Ruppert-Prakash reagent (TMS-CF3) reacting in a constructive manner with an amide and enables synthesis of TMFKs without risk of over-trifluoromethylation.
- Rudzinski, Diandra M.,Kelly, Christopher B.,Leadbeater, Nicholas E.
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supporting information
p. 9610 - 9612
(2012/10/29)
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- Highly efficient asymmetric epoxidation of electron-deficient α,β-enones and related applications to organic synthesis
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The asymmetric epoxidation of electrondeficient olefins has been achieved using inexpensive and readily available prolinols as catalysts with good to excellent yields and enantioselectivities. The utility of the resulting chiral epoxides was illustrated b
- Zheng, Changwu,Li, Yawen,Yang, Yingquan,Wang, Haifeng,Cui, Haifeng,Zhang, Junkang,Zhao, Gang
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supporting information; experimental part
p. 1685 - 1691
(2011/02/25)
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- Reaction of 1,2-unsaturated trifluoromethyl ketones and their conversion to 1-(trifluoromethyl)furan derivatives
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A novel synthetic approach leading to 1-(trifluoromethyl)furan derivatives is reported. 4-Aryl-1,1,1-trifluorobut-3-en-2-one was iodinated and subsequently reduced to give the corresponding alcohol. The resultant iodo compound was then subjected to coupli
- Zhang, Dehui,Yuan, Chengye
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p. 3916 - 3924
(2008/02/13)
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- Preparation of fluoroalkyl imines, amines, enamines, ketones, α-amino carbonyls, and α-amino acids from primary enamine phosphonates
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A simple method for preparation of fluoroalkyl β-enaminophosphonates 1 from alkylphosphonates 2 and perfluoroalkyl nitriles 3 is reported. Olefination reaction of functionalized phosphates 1 with aldehydes gives α,β-unsaturated imines 5. Acid hydrolysis of these fluoroalkyl derivatives 5 affords α,β-unsaturated ketones 6, while their selective reduction with hydrides leads to the formation of allylamines 7, enamines 8, and saturated ketones 9 or amines 10. Selective oxidative cleavage of the carbon-carbon double bond of allylamines 7 gives fluorinated α-amino aldehydes 12, α-amino ketones 13, or α-amino acid derivatives 14.
- Palacios, Francisco,Ochoa De Retana, Ana Maria,Pascual, Sergio,Oyarzabal, Julen
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p. 8767 - 8774
(2007/10/03)
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- A convenient one-pot synthesis of 6-trifluoromethyl-pyridines
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α,β-Unsaturated trifluoromethyl ketones (1) react with primary enamines (2) such as β-aminocrotononitrile and β-aminocrotonates in the presence of phosphorus oxychloride / pyridine adsorbed on silica gel and manganese dioxide, providing good to high yield
- Katsuyama, Isamu,Ogawa, Seiya,Nakamura, Hiroko,Yamaguchi, Yoshihiro,Funabiki, Kazumasa,Matsui, Masaki,Muramatsu, Hiroshige,Shibata, Katsuyoshi
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p. 779 - 785
(2007/10/03)
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