- 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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- Synthesis of Dithiolethiones and Identification of Potential Neuroprotective Agents via Activation of Nrf2-Driven Antioxidant Enzymes
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Oxidative stress is implicated in the pathogenesis of a wide variety of neurodegenerative disorders, and accordingly, dietary supplement of exogenous antioxidants or/and upregulation of the endogenous antioxidant defense system are promising for therapeutic intervention or chemoprevention of neurodegenerative diseases. Nrf2, a master regulator of the cellular antioxidant machinery, cardinally participates in the transcription of cytoprotective genes against oxidative/electrophilic stresses. Herein, we report the synthesis of 59 structurally diverse dithiolethiones and evaluation of their neuroprotection against 6-hydroxydopamine-or H2O2-induced oxidative damages in PC12 cells, a neuron-like rat pheochromocytoma cell line. Initial screening identified compounds 10 and 11 having low cytotoxicity but conferring remarkable protection on PC12 cells from oxidative-mediated damages. Further studies demonstrated that both compounds upregulated a battery of antioxidant genes as well as corresponding genes' products. Significantly, silence of Nrf2 expression abolishes cytoprotection of 10 and 11, indicating targeting Nrf2 activation is pivotal for their cellular functions. Taken together, the two lead compounds discovered here with potent neuroprotective functions against oxidative stress via Nrf2 activation merit further development as therapeutic or chemopreventive candidates for neurodegenerative disorders.
- Bai, Feifei,Fang, Jianguo,Song, Zi-Long,Zhang, Baoxin
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p. 2214 - 2231
(2020/03/06)
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