The arylation of C(sp2)–H and C(sp3)–H bonds in carboxylic acids catalyzed by Pd(II) with 4-aminobentriazole as the directing group was investigated. In addition to activation of the C(sp2)–H bond, selectivearylation of alkyl carboxylic acids and amino acids in the β position can also be achieved. This strategy involved a 5,5-bicyclic Pd intermediate complex whose structure was determined by X-ray
A number of quinolone derivatives have been reported to possess anti-mycobacterial activity. Generally. Mycobacterium tuberculosis isolates expressing resistance to both isoniazid and rifampin are susceptible to fluoroquinolones. Benzotriazole is a hetero-bicyclic aromatic ring endowed with interesting chemical and biological properties and pharmacological activities. In a preliminary study we have recently reported the activity of triazolo[4,5-h]quinolone-carboxylic acids, a new class of benzotriazole derivatives active against multi-drug resistant M. tuberculosis (MDR-Mtb). In this study we confirm that this novel class of quinolones is endowed with a selective anti-mycobacterial activity, coupled with absence of cytotoxicity.The SAR analysis of the new derivatives in comparison with the previous series shows that the methyl group is the most effective substituent in both N-3 and N-9 positions of the ring system. (C) 2010 Elsevier Masson SAS. All rights reserved.
4-Aminobenzotriazole (ABTA) as a Removable Directing Group for Palladium-Catalyzed Aerobic Oxidative C–H Olefination
作者:Zhuo Wang、Xiaohan Ye、Meina Jin、Qi Tang、Shengyu Fan、Zhiguang Song、Xiaodong Shi
DOI:10.1021/acs.orglett.2c00285
日期:2022.5.6
4-Aminobenzotriazole (ABTA) was applied as an effective removabledirectinggroup (DG) in Pd-catalyzed C–H activation for the first time. Compared with the widely applied pyridine and quinoline analogs, ABTA showed significantly improved reactivity, achieving aerobic oxidative C–H olefination in excellent yields (up to 95% vs <50% with other reported DGs under identical conditions). Using this new