- HYDROGENATION PROCESS OF OXIME DERIVATIVES
-
The present invention relates to a novel process for the iridium-catalysed hydrogenation of oximes. The invention also relates to novel iridium catalysts for use in the iridium-catalysed hydrogenation of oximes and to processes of preparation of these cat
- -
-
Page/Page column 33
(2020/06/01)
-
- Accessing Difluoromethylated and Trifluoromethylated cis-Cycloalkanes and Saturated Heterocycles: Preferential Hydrogen Addition to the Substitution Sites for Dearomatization
-
Reported here is a straightforward process in which a cyclic (alkyl)(amino)carbene/Rh catalyst system facilitates the preferential addition of hydrogen to the substitution sites of difluoromethylated and trifluoromethylated arenes and heteroarenes, leading to dearomative reduction. This strategy enables the diastereoselective synthesis of cis-difluoromethylated and cis-trifluoromethylated cycloalkanes and saturated heterocycles, and even allows formation of all-cis multi-trifluoromethylated cyclic products with a defined equatorial orientation of the di- and trifluoromethyl groups. Deuterium-labeling studies indicate that hydrogen preferentially attacks the substitution sites of planar arenes, resulting in dearomatization, possibly with heterogeneous Rh as the reactive species, followed by either reversible or irreversible hydrogen addition to the nonsubstitution sites.
- Zhang, Xue,Ling, Liang,Luo, Meiming,Zeng, Xiaoming
-
supporting information
p. 16785 - 16789
(2019/11/11)
-
- Method for synthesizing cis-trifluoromethylcyclohexane derivatives and heterocyclic compounds by hydrogenation
-
The invention discloses a method for synthesizing cis-trifluoromethylcyclohexane derivatives and heterocyclic compounds by hydrogenation. The method is characterized in that trifluoromethylaromatic hydrocarbons or trifluoromethyl heterocyclic compounds ar
- -
-
Paragraph 0021-0023; 0127-0129
(2019/10/23)
-
- The reaction of cyclic imines with the Ruppert-Prakash reagent. Facile approach to α-trifluoromethylated nornicotine, anabazine, and homoanabazine
-
We have demonstrated that the Ruppert-Prakash reagent is able to react with a number of cyclic imines under acidic condition to afford the corresponding α-trifluoromethyl derivatives of nitrogen heterocycles. 5-7-Membered cyclic imines bearing various alkyl, aryl or heterocyclic group were successfully involved in this transformation. Novel trifluoromethylated analogues of nicotine, anabasine, and homoanabasine alkaloids were synthesized.
- Shevchenko, Nikolay E.,Vlasov, Katja,Nenajdenko, Valentine G.,R?schenthaler, Gerd-Volker
-
experimental part
p. 69 - 74
(2011/02/27)
-
- Practical synthesis of α-perfluoroalkyl cyclic imines and amines
-
A convenient and simple approach for the preparation of -CF3and C2F5 substituted pyrrolines, tetrahydropyridines, tetrahydroazepine is described. Claisen condensation of N-protected cyclic amides with esters of perfluorocarboxylic acids followed by deprotection and decarboxylation in acidic media leads to the desired products. Reduction of these imines permits to obtain 5-, 6-, and 7-membered cyclic amines with - CF3and C2F5 group in good to moderate overall yields. Georg Thieme Verlag Stuttgart - New York.
- Shevchenko, Nikolay E.,Balenkova, Elisabeth S.,Roeschenthaler, Gerd-Volker,Nenajdenko, Valentine G.
-
experimental part
p. 120 - 126
(2010/04/05)
-
- A simple stereoselective route to α-trifluoromethyl analogues of piperidine alkaloids
-
The highly diastereoselective synthesis of five trifluoro-substituted analogues of mono-, di-, and trisubstituted piperidine alkaloids was accomplished in two to four steps from 2-trifluoromethyl keto-protected 4-piperidones, prepared by an intramolecular
- Bariau, Annabelle,Jatoi, Wahid Bux,Calinaud, Pierre,Troin, Yves,Canet, Jean-Louis
-
p. 3421 - 3433
(2007/10/03)
-