- Decarboxylative Cyanation of Aliphatic Carboxylic Acids via Visible-Light Flavin Photocatalysis
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An operationally simple method is disclosed for the decarboxylative cyanation of aliphatic carboxylic acids at room temperature. Riboflavin tetraacetate, which is an inexpensive organic photocatalyst, promotes the oxidation of carboxylic acids upon visible-light activation. After decarboxylation, the generated radicals are trapped by TsCN, yielding the desired nitriles without any further additive, in a redox-neutral process. Importantly, this protocol can be adapted to flow conditions.
- Ramirez, Nieves P.,K?nig, Burkhard,Gonzalez-Gomez, Jose C.
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supporting information
(2019/03/08)
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- Room temperature decarboxylative cyanation of carboxylic acids using photoredox catalysis and cyanobenziodoxolones: a divergent mechanism compared to alkynylation
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The one-step conversion of aliphatic carboxylic acids to the corresponding nitriles has been accomplished via the merger of visible light mediated photoredox and cyanobenziodoxolones (CBX) reagents. The reaction proceeded in high yields with natural and non-natural α-amino and α-oxy acids, affording a broad scope of nitriles with excellent tolerance of the substituents in the α position. The direct cyanation of dipeptides and drug precursors was also achieved. The mechanism of the decarboxylative cyanation was investigated both computationally and experimentally and compared with the previously developed alkynylation reaction. Alkynylation was found to favor direct radical addition, whereas further oxidation by CBX to a carbocation and cyanide addition appeared more favorable for cyanation. A concerted mechanism is proposed for the reaction of radicals with EBX reagents, in contrast to the usually assumed addition elimination process.
- Le Vaillant, Franck,Wodrich, Matthew D.,Waser, Jér?me
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p. 1790 - 1800
(2017/03/09)
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- DICYCLOAZAALKANE DERIVATES, PREPARATION PROCESSES AND MEDICAL USES THEREOF
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Disclosed are new dicycloazaalkane derivates represented by general formula (I), preparation processes and pharmaceutical compositions containing them, and the uses for treatment especially for dipeptidyl peptidase inhibitor (DPP-IV), in which each substitute group of general formula (I) is as defined in specification.
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Page/Page column 39
(2010/11/17)
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- NOVEL PROCESSES FOR THE PREPARATION OF DPP IV INHIBITORS
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The present invention relates to novel processes for preparing DPP-IV inhibitors having the structure of formula I, and pharmaceutically acceptable salt thereof, which are useful for treatment of Type 2 diabetes.
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Page/Page column 43
(2008/06/13)
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- NEW COMPOUNDS
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The present invention relates to the novel compounds of the general formula (I) possessing DPP-IV inhibitory activity. These compounds contain tropane building blocks.
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