- Combined Photoredox and Carbene Catalysis for the Synthesis of α-Amino Ketones from Carboxylic Acids
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α-Amino ketone moieties are present in many pharmacologically active molecules, but their synthesis is challenging. Herein, we report a mild, operationally simple method for direct acylation of α-amino C(sp3)-H bonds from carboxylic acids via the merger of carbene and photoredox catalysis. Specifically, cross-coupling reactions between a wide range of carboxylic acids, a class of feedstock chemicals, and readily available N-alkyl anilines by means of single-electron N-heterocyclic carbene catalysis combined with photocatalysis provided access to structurally diverse α-amino ketones. The method features a broad substrate scope and is compatible with a wide array of functional groups. To demonstrate the potential applications of the method, we subjected one of the α-amino ketone products to further transformations.
- Wang, Xiaochen,Zhu, Binbing,Liu, Yuxiu,Wang, Qingmin
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p. 2522 - 2531
(2022/02/17)
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- Light-Driven Carbene Catalysis for the Synthesis of Aliphatic and α-Amino Ketones
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Single-electron N-heterocyclic carbene (NHC) catalysis has gained attention recently for the synthesis of C?C bonds. Guided by density functional theory and mechanistic analyses, we report the light-driven synthesis of aliphatic and α-amino ketones using single-electron NHC operators. Computational and experimental results reveal that the reactivity of the key radical intermediate is substrate-dependent and can be modulated through steric and electronic parameters of the NHC. Catalyst potential is harnessed in the visible-light driven generation of an acyl azolium radical species that undergoes selective coupling with various radical partners to afford diverse ketone products. This methodology is showcased in the direct late-stage functionalization of amino acids and pharmaceutical compounds, highlighting the utility of single-electron NHC operators.
- Bay, Anna V.,Cheong, Paul Ha-Yeon,Farah, Abdikani Omar,Fitzpatrick, Keegan P.,González-Montiel, Gisela A.,Scheidt, Karl A.
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supporting information
p. 17925 - 17931
(2021/07/17)
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- A new method for synthesizing ring-propyl bromide (by machine translation)
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The invention relates to a new method for synthesizing ring-propyl bromide of: the ring n-propyl formate reaction with carbonyl diimidazole generating cyclopropanecarboxylic acyl imidazole, the intermediate is then mixed together with trichloro curafume, maintain 10 °C to 140 °C slowly dropping under the conditions of the free radical bromination reaction of deacidifying cyclopropyl bromine thick obtained after, through simple atmospheric distillation to obtain the purity 99% product of the above. The mild reaction conditions, conventional reagent used is cheap and easy to obtain, by avoiding the use of oxidized mercury squeezing, is suitable for industrial production. (by machine translation)
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Paragraph 0024; 0025; 0026
(2017/01/02)
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- THIAZOLYL-DIHYDRO-INDAZOLE
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The present invention relates to new thiazolyl-dihydro-indazoles of general formula (I) wherein the groups R1, R2 and R3 have the meanings given in the claims and specification, the tautomers, racemates, enantiomers, diastereomers and the mixtures thereof, and optionally the pharmacologically acceptable acid addition salts, solvates and hydrates thereof, and processes for preparing these thiazolyl-dihydro-indazoles and the use thereof as pharmaceutical compositions.
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Page/Page column 18
(2008/06/13)
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- THIAZOLYL-DIHYDRO-INDAZOLE
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Disclosed are compounds of general formula (I), wherein the groups R1, R2, Ra and Rb have the meanings given in the claims and specification, the tautomers, racemates, enantiomers, diastereomers and the mixtures thereof, and optionally the pharmacologically acceptable acid addition salts, solvates and hydrates thereof, and processes for preparing these thiazolyl-dihydro-indazoles and the use thereof as pharmaceutical compositions.
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Page/Page column 17
(2008/06/13)
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- Enantioselective synthesis of α-amino acids from N-tosyloxy β-lactams derived from β-keto esters
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A novel synthetic sequence has been developed to convert simple β-keto esters into enantiomerically enriched α-amino acids. The key features of this sequence include the addition of azide to the C3 position of β-keto ester derived N-tosyloxy-β-lactams through a concomitant nucleophilic addition/N-O bond reduction reaction, a mild CsF-induced N1 benzylation of α-azido monocyclic β-lactams, the preparation of α-keto-β-lactams through a novel four-step sequence from the corresponding 3-azido-1-benzyl-β-lactams, and TEMPO-mediated ring expansion of these compounds to the corresponding N-carboxy anhydrides (NCAs). In addition, the synthesis, isolation, and characterization of unusual 3-imino and 3-chloramino-β-lactams is reported.
- Durham, Timothy B.,Miller, Marvin J.
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- Processes for preparing intermediates
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The invention relates to processes for the preparation of compounds of formula (I), wherein R1and R2are as defined in the description.
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Page/Page column 8
(2010/01/31)
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- New Tetracyclic Derivatives of Imidazobenzodiazepines and of Imidazothienodiazepines
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The synthesis of new tetracyclic 1,4-diazepine derivatives is described.In these compounds, an additional five-membered heterocycle is fused on the known tricyclic ring systems imidazobenzodiazepine and imidazothienodiazepine.Many of these new compounds display a very high affinity to the benzodiazepine receptor in mammals.
- Gerecke, Max,Kyburz, Emilio,Borer, Rene,Gassner, Walter
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p. 693 - 722
(2007/10/02)
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