- New synthetic access to 3-fluoroalkyl-5-pyrazolecarboxylates and carboxylic acids
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A novel process for preparing 3-fluoroalkyl-5-pyrazolecarboxylates and carboxylic acids is hereby presented. Easily accesible α-fluorinated ketimines were condensed with oxalyl monochloride derivatives, and the obtained vinamides underwent acid-catalyzed cyclization with substituted hydrazines. This highly efficient protocol can also be used for non-fluorinated C-3 and C-5 substituents.
- Herrera, Alberto Gómez,Schmitt, Etienne,Panossian, Armen,Vors, Jean-Pierre,Pazenok, Sergii,Leroux, Frédéric R.
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- A Major Advance in the Synthesis of Fluoroalkyl Pyrazoles: Tuneable Regioselectivity and Broad Substitution Patterns
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A novel approach towards highly functionalized fluoroalkyl pyrazoles was developed by using fluoroalkyl amino reagents in combination with a variety of fluorinated ketimines. Tuneable introduction of fluoroalkyl groups in the 3- and 5-positions was possible by using vinamidinium intermediates or the corresponding enamino ketones after hydrolysis. These high-value building blocks can give rise to a large number of analogues for bioactivity screening and discovering new heterocyclic bioactive ingredients in various life science fields.
- Schmitt, Etienne,Panossian, Armen,Vors, Jean-Pierre,Funke, Christian,Lui, Norbert,Pazenok, Sergiy,Leroux, Frédéric R.
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supporting information
p. 11239 - 11244
(2016/08/03)
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- PROCESS FOR PREPARING 3,5-BIS(HALOALKYL)PYRAZOLE DERIVATIVES FROM α,α-DIHALOAMINES AND KETIMINES
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Process for preparine3,5-bis(haloalkyl)pyrazolederivatives from a,a-dihaloamines and ketimines The present invention relates to a novel process for preparing 3,5-bis(haloalkyl)pyrazole derivatives from a,a-dihaloamines and ketimines. Intermedaites used in the process are also claimed.
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Page/Page column 17
(2015/11/24)
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- PROCESS FOR PREPARING 3,5-BIS(HALOALKYL)PYRAZOLES VIA ACYLATION OF KETIMINES
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The present invention relates to a novel process for preparing 3,5-bis(haloalkyl)pyrazole derivatives of the formula (Ia) and (Ib), via acylation of ketimines.
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Page/Page column 11-12
(2016/01/01)
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- Chemoenzymatic dynamic kinetic resolution of α-trifluoromethylated amines: Influence of substitutions on the reversed stereoselectivity
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Enzymatic resolution of α-trifluoromethylated amines via kinetic resolution (KR), dynamic kinetic resolution (DKR) employing CALB-Pd/Al 2O3, and a one-pot sequential process of KR/DKR/KR was investigated comparatively for the first time. Although CALB-catalyzed KR of α-trifluoromethylated amines with substituents of methyl (1a), isopropyl (1c), phenyl (1d) and benzyl group (1e) can provide good stereoselectivity factors E from 31 to >200 respectively, DKR and sequential process of KR/DKR/KR possess better practical application potential because of the higher conversion (62%-84%) and the similar enantiomeric excesses (90%-99%). The enantiopreference and inversion for the α-trifluoromethylated amines displayed by CALB were observed and explained by docking modes. Namely, for 1,1,1-trifluoro-2-propylamine (1a), the product amide with R-configuration was obtained, and the enantiopreference was converted to S for the amines (1b-1e) with substituents larger than methyl group. The catalysts recycle, and scale-up experiments were demonstrated successfully. All these results indicated the high efficiency and green feature of this enzymatic process, and its application significance.
- Cheng, Guilin,Xia, Bo,Wu, Qi,Lin, Xianfu
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p. 9820 - 9828
(2013/09/02)
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- Straightforward synthesis of 1-alkyl-2-(trifluoromethyl)aziridines starting from 1,1,1-trifluoroacetone
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An efficient and straightforward approach towards the synthesis of 1-alkyl-2-(trifluoromethyl)aziridines starting from 1,1,1-trifluoroacetone via imination, α-chlorination, hydride reduction and ring closure was developed. In addition, novel primary β-iodo amines were obtained by regioselective ring opening of these 2-(trifluoromethyl)aziridines using alkyl iodides, and their synthetic potential was demonstrated by converting them into novel α-CF3-β-phenylethylamines upon treatment with lithium diphenylcuprate.
- Kenis, Sara,D'Hooghe, Matthias,Verniest, Guido,Nguyen, Vinh Duc,Thi, Tuyet Anh Dang,Nguyen, Tuyen Van,Kimpe, Norbert De
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experimental part
p. 7217 - 7223
(2011/11/06)
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- The Ugi reaction with CF3-carbonyl compounds: effective synthesis of α-trifluoromethyl amino acid derivatives
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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.
- Gulevich, Anton V.,Shevchenko, Nikolay E.,Balenkova, Elisabeth S.,R?schenthaler, Gerd-Volker,Nenajdenko, Valentine G.
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supporting information; scheme or table
p. 11706 - 11712
(2009/04/06)
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- Biomimetic reductive amination of fluoro aldehydes and ketones via [1,3]-proton shift reaction. Scope and limitations
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A systematic study of azomethine-azomethine isomerizations of the N-benzylimines 2, derived from fluorinated aldehydes or ketones and benzylamine, has been made. The results reveal that, in sharp contrast to hydrocarbon analogs, fluorinated imines of 2 in triethylamine solution undergo isomerizations to give the corresponding N-benzylidene derivatives 5 (for 5/2 K > 32) in good isolated yields. The rates of the isomerizations depend on the starting imine structures and increase in the following order: aryl perfluoroalkyl ketimine 2m, per(poly)fluoroalkyl aldimine 2a,d-g, perfluoroaryl aldimine 2h, alkyl perfluoroalkyl ketimine 2i,j. The presence of chlorine or bromine atoms in the α-position to the C=N double bond of the starting imine favors a dehydrohalogenation reaction, giving rise to unsaturated products 6-9. The azomethine-azomethine isomerization was studied and proven to proceed essentially (>98%) intramolecularly with isotope exchange experiments. High chemical yields, the simplicity of the experimental procedure, and the low cost of all reagents employed make this biomimetic transamination of fluorocarbonyl compounds a practical method for preparing fluorine-containing amines of biological interest.
- Ono, Taizo,Kukhar, Valery P.,Soloshonok, Vadim A.
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p. 6563 - 6569
(2007/10/03)
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- AZOMETHINE-AZOMETHINE ISOMERIZATION IN THE SERIES OF FLUORINE-CONTAINING N-BENZYLIMINES
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The reaction of N-benzyltriphenylphosphine imide with fluorine-containing carbonyl compounds leads to the corresponding N-benzylimines.The latter readily isomerize under the influence of bases to N-benzylidene derivatives.
- Soloshonok, V. A.,Gerus, I. I.,Yagupol'skii, Yu. L.,Kukhar', V. G.
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p. 895 - 899
(2007/10/02)
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