1997-85-9Relevant academic research and scientific papers
Nucleophile-directed selective transformation of cis-1-tosyl-2- tosyloxymethyl-3-(trifluoromethyl)aziridine into aziridines, azetidines, and benzo-fused dithianes, oxathianes, dioxanes, and (thio)morpholines
Kenis, Sara,D'Hooghe, Matthias,Verniest, Guido,Reybroeck, Maaike,Dang Thi, Tuyet Anh,Pham The, Chinh,Thi Pham, Tham,T?rnroos, Karl W.,Van Tuyen, Nguyen,De Kimpe, Norbert
, p. 5966 - 5971 (2013)
A five-step procedure for the synthesis of cis-1-tosyl-2-tosyloxymethyl-3- (trifluoromethyl)aziridine was developed, starting from 1-ethoxy-2,2,2- trifluoroethanol, involving imination, aziridination, ester reduction, hydrogenation, and N-,O-ditosylation steps. Further synthetic elaborations revealed a remarkable difference in the reactivity of cis-1-tosyl-2- tosyloxymethyl-3-(trifluoromethyl)aziridine with respect to aromatic sulfur and oxygen nucleophiles, thus enabling the selective deployment of this versatile substrate as a building block for the synthesis of functionalized aziridines, azetidines, and benzo-fused dithianes, oxathianes, dioxanes, and (thio)morpholines. Copyright
N-Ammonium Ylide Mediators for Electrochemical C-H Oxidation
Saito, Masato,Kawamata, Yu,Meanwell, Michael,Navratil, Rafael,Chiodi, Debora,Carlson, Ethan,Hu, Pengfei,Chen, Longrui,Udyavara, Sagar,Kingston, Cian,Tanwar, Mayank,Tyagi, Sameer,McKillican, Bruce P.,Gichinga, Moses G.,Schmidt, Michael A.,Eastgate, Martin D.,Lamberto, Massimiliano,He, Chi,Tang, Tianhua,Malapit, Christian A.,Sigman, Matthew S.,Minteer, Shelley D.,Neurock, Matthew,Baran, Phil S.
supporting information, p. 7859 - 7867 (2021/05/26)
The site-specific oxidation of strong C(sp3)-H bonds is of uncontested utility in organic synthesis. From simplifying access to metabolites and late-stage diversification of lead compounds to truncating retrosynthetic plans, there is a growing need for new reagents and methods for achieving such a transformation in both academic and industrial circles. One main drawback of current chemical reagents is the lack of diversity with regard to structure and reactivity that prevents a combinatorial approach for rapid screening to be employed. In that regard, directed evolution still holds the greatest promise for achieving complex C-H oxidations in a variety of complex settings. Herein we present a rationally designed platform that provides a step toward this challenge using N-ammonium ylides as electrochemically driven oxidants for site-specific, chemoselective C(sp3)-H oxidation. By taking a first-principles approach guided by computation, these new mediators were identified and rapidly expanded into a library using ubiquitous building blocks and trivial synthesis techniques. The ylide-based approach to C-H oxidation exhibits tunable selectivity that is often exclusive to this class of oxidants and can be applied to real-world problems in the agricultural and pharmaceutical sectors.
Formylation of fluoroalkyl imines through visible-light-enabled H-atom transfer catalysis: Access to fluorinated α-amino aldehydes
Yang, Sen,Zhu, Shuangyu,Lu, Dengfu,Gong, Yuefa
supporting information, p. 2019 - 2024 (2019/04/10)
A visible-light-enabled catalytic formylation of fluoroalkyl imines is developed. With readily accessible starting materials and organocatalysts, this method provides a general approach to masked fluoroalkyl amino aldehydes. A synergistic catalytic effect
Trifluoromethyl syn- or anti-γ-amino alcohols by one-pot solvent-free Mannich-type reactions under temperature control
Fioravanti, Stefania,Parise, Luca,Pelagalli, Alessia,Pellacani, Lucio,Trulli, Laura
, p. 29312 - 29318 (2015/04/14)
Starting from trifluoroacetaldehyde ethyl hemiacetal, chiral amines and suitable aldehydes, diastereomerically pure fluorinated syn- or anti-γ-amino alcohols can be obtained by a friendly one-pot solvent-free l-proline catalysed Mannich-type reaction only
Highly diastereo- and enantioselective vinylogous Mannich reactions of fluorinated aldimines with siloxyfurans
Zhao, Qian-Yi,Yuan, Zhi-Liang,Shia, Min
supporting information; experimental part, p. 637 - 643 (2011/04/25)
A highly regio- and enantioselective asymmetric vinylogous Mannich reaction of readily available fluorinated aldimines bearing a chiral auxiliary [(S)-1-phenylethyl group] with siloxyfurans to afford chiral fluorine-containing γ-butenolide or γ-lactone derivatives has been developed in the presence of silver acetate (10 mol%) and axially chiral phosphine-oxazoline ligand L1 (11 mol%). In most cases, the corresponding fluorinated adducts were obtained in high yields, good to excellent enantiomeric excesses and up to > 20:1 dr.
The Ugi reaction with CF3-carbonyl compounds: effective synthesis of α-trifluoromethyl amino acid derivatives
Gulevich, Anton V.,Shevchenko, Nikolay E.,Balenkova, Elisabeth S.,R?schenthaler, Gerd-Volker,Nenajdenko, Valentine G.
supporting information; scheme or table, p. 11706 - 11712 (2009/04/06)
The Ugi reaction with CF3-carbonyl compounds is described in detail. The method is efficient for the multicomponent preparation of α-trifluoromethyl (Tfm) amino acids, α-Tfm containing dipeptides, and iminodicarboxylic acids. In addition, the first protected CF3-opine derivative was prepared. The scope, limitations, and stereochemistry of the approach are discussed.
BF3-promoted aromatic substitution of N-alkyl α-trifluoromethylated imine: Facile synthesis of 1-aryl-2,2,2-trifluoroethylamines
Gong, Yuefa,Kato, Katsuya,Kimoto, Hiroshi
, p. 2637 - 2645 (2007/10/03)
The aromatic substitution of three representative N-alkyl trifluoromethyl imines 1a-c (R: a, benzyl; b, benzhydryl; c, methyl), obtained from primary alkyl amines and trifluoroacetaldehyde ethyl hemiacetal, was used to investigate the preparation of 1-aryl-2,2,2-trifluoroethylamines. In the presence of BF3·OEt2, the reaction of imine 1 with various aromatic compounds proceeded smoothly at room temperature, giving N-alkyl-1-aryl-2,2,2-trifluoroethylamines in moderate-to-high yields. Moreover, successful regioselective removal of N-benzyl and N-benzhydryl groups was achieved by hydrolysis in hydrochloric acid or by palladium-catalyzed hydrogenolysis.
Friedel-Crafts reaction of N-alkyl trifluoroacetaldehyde imine: Facile synthesis of 1-aryl-2,2,2-trifluoroethylamines
Gong, Yuefa,Kato, Katsuya,Kimoto, Hiroshi
, p. 1058 - 1060 (2007/10/03)
N-Alkyl trifluoroacetaldehyde imines 1a,b (R: a, benzyl; b, diphenylmethyl), prepared from trifluoroacetaldehyde ethyl hemiacetal (TFAE) and primaryl amines, readily reacted with electron-rich heteroarenes, N,N- dimethylaniline and phenols in the presence of BF3. Product analysis showed moderate to high yields of N-alkyl-1-aryl-2,2,2-trifluoroethylamines 2-7. Hydrolysis of representative N-diphenylmethyl amines 5b and 7b, respectively yielded the 1-aryl-2,2,2-trifluoroethylamines 10 and 11.
A practical route to fluoroalkyl- and fluoroarylamines by base-catalyzed [1,3]-proton shift reaction
Soloshonok,Soloshonok, Vadim A.,Kirilenko,Kirilenko, Alexander G.,Kukhar,Kukhar, Valery P.,Resnati,Resnati, Giuseppe
, p. 3119 - 3122 (2007/10/02)
The base-catalyzed [1,3]-proton shift reaction is shown to be an efficient general approach to fluoroalkyl and fluoroaryl amines starting from appropriate carbonyl compounds and benzylamine.
