96107-01-6Relevant academic research and scientific papers
Radical Trifluoroacetylation of Alkenes Triggered by a Visible-Light-Promoted C–O Bond Fragmentation of Trifluoroacetic Anhydride
Jeschke, Gunnar,Katayev, Dmitry,N?tel, Nicolas Yannick,Rombach, David,Zhang, Kun
supporting information, p. 22487 - 22495 (2021/09/09)
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.
SYNTHESIZING METHOD α,β-UNSATURATED KETONE COMPOUND
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Paragraph 0018; 0030; 0050-0052, (2020/10/19)
The present invention relates to a method for preparing an andalpha;,andbeta;-unsaturated ketone compound comprising the step of synthesizing an andalpha;,andbeta;-unsaturated ketone compound represented by Formula 3 below by reacting a styrene compound represented by Formula 1 below with a carboxylic anhydride represented by Formula 2 below. In the Formula 1, R_1 and R_2 are each independently substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, or substituted or unsubstituted heteroalkyl, and in the Formula 2, A is F, Cl, or F and Cl, and n is 1 to 10.COPYRIGHT KIPO 2021
Evaluating aryl esters as bench-stable C(1)-ammonium enolate precursors in catalytic, enantioselective Michael addition-lactonisations
Young, Claire M.,Taylor, James E.,Smith, Andrew D.
, p. 4747 - 4752 (2019/05/24)
An evaluation of a range of aryl, alkyl and vinyl esters as prospective C(1)-ammonium enolate precursors in enantioselective Michael addition-lactonisation processes with (E)-trifluoromethylenones using isothiourea catalysis is reported. Electron deficient aryl esters are required for reactivity, with 2,4,6-trichlorophenyl esters providing optimal product yields. Catalyst screening showed that tetramisole was the most effective isothiourea catalyst, giving the desired dihydropyranone product in excellent yield and stereoselectivity (up to 90 : 10 dr and 98 : 2 er). The scope and limitations of this process have been evaluated, with a range of diester products being generated after ring-opening with MeOH to give stereodefined dihydropyranones with excellent stereocontrol (10 examples, typically ～90 : 10 dr and >95 : 5 er).
4-Ethoxy-1,1,1-trifluoro-3-buten-2-one (ETFBO), a Versatile Precursor for Trifluoromethyl-Substituted Heteroarenes - A Short Synthesis of Celebrex (Celecoxib)
Sommer, Heiko,Braun, Max,Schr?der, Benjamin,Kirschning, Andreas
supporting information, p. 121 - 125 (2017/10/07)
4-Ethoxy-1,1,1-trifluoro-3-buten-2-one (ETFBO) serves as a trifluoromethyl-containing building block for the preparation of trifluoromethyl-substituted thiophenes, furans, pyrrols, and piperazines. Key steps are an addition-elimination reaction to ETFBO followed by the thiazolium-catalyzed Stetter reaction. The scope of this chemistry was demonstrated in a new synthetic approach towards the COX-2 selective, nonsteroidal anti-inflammatory drug Celebrex (celecoxib).
An efficient route to 3-trifluoromethylpyrazole via cyclization/1,5-H shift and its applications in the synthesis of bioactive compounds
Wang, Yongdong,Han, Jing,Chen, Jie,Cao, Weiguo
, p. 8256 - 8262 (2015/10/05)
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.
Isothiourea-mediated one-pot synthesis of trifluoromethyl substituted 2-pyrones
Yeh, Pei-Pei,Daniels, David S. B.,Cordes, David B.,Slawin, Alexandra M. Z.,Smith, Andrew D.
supporting information, p. 964 - 967 (2014/03/21)
A one-pot isothiourea-mediated Michael addition/lactonization/thiol elimination cascade sequence for the formation of 4,6-disubstituted and 3,4,6-trisubstituted 2-pyrones from (phenylthio)acetic acids and α,β-unsaturated trifluoromethyl ketones is described. The synthesis of a COX-2 inhibitor and the wide-ranging derivatization of the 2-pyrone moiety to trifluoromethyl substituted aromatics and heteroaromatics is also disclosed.
Dehydrogenation of perfluoroalkyl ketones by using a recyclable oxoammonium salt
Hamlin, Trevor A.,Kelly, Christopher B.,Leadbeater, Nicholas E.
supporting information, p. 3658 - 3661 (2013/07/19)
A novel dehydrogenation reaction of perfluoroalkyl ketones by the oxoammonium salt 4-acetylamino-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate (4-NHAc-TEMPO+BF4-, Bobbitt's salt, 1) is described. The reaction proceeds under mildly basic conditions and appears to be unique to perfluoroalkyl ketones. A proposed mechanism for this unusual transformation is given. The byproduct of the reaction, 4-acetylamino-2,2,6,6-tetramethyl-1-piperidinyloxy (1a), can easily be recovered and used to regenerate the oxoammonium salt. The dehydrogenation of perfluoroalkyl ketones by using an oxoammonium salt is reported. The reaction proceeds under mildly basic conditions and affords α,β-unsaturated products in fair to excellent yields. The reaction likely proceeds through a two-step sequence. The spent oxidant can easily be recovered and used to regenerate the oxoammonium salt. Copyright
Synthesis of tri- and tetrasubstituted pyrazoles via Ru(II) catalysis: Intramolecular aerobic oxidative C-N coupling
Hu, Jiantao,Chen, Shi,Sun, Yonghui,Yang, Jing,Rao, Yu
supporting information, p. 5030 - 5033,4 (2012/12/12)
An unprecedented ruthenium(II)-catalyzed intramolecular oxidative C-N coupling method has been developed for the facile synthesis of a variety of synthetically challenging tri- and tetrasubstituted pyrazoles. Dioxygen gas is employed as the oxidant in this transformation. The reaction demonstrates excellent reactivity, functional group tolerance, and high yields.
Highly efficient asymmetric epoxidation of electron-deficient α,β-enones and related applications to organic synthesis
Zheng, Changwu,Li, Yawen,Yang, Yingquan,Wang, Haifeng,Cui, Haifeng,Zhang, Junkang,Zhao, Gang
supporting information; experimental part, p. 1685 - 1691 (2011/02/25)
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
Reaction of 1,2-unsaturated trifluoromethyl ketones and their conversion to 1-(trifluoromethyl)furan derivatives
Zhang, Dehui,Yuan, Chengye
, p. 3916 - 3924 (2008/02/13)
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
