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The electrochemical oxidative radical-radical cross-coupling of sulfonyl hydrazides with diselenides for the synthesis of selenosulfonates was successfully accomplished. The method is applicable to a wide range of aromatic/aliphatic sulfonyl hydrazides and diselenides, providing products in good to excellent yields. Notably, this protocol stands out for its green and sustainable nature, as it does not rely on transition metals and oxidizing agents, and the starting materials are cost-effective and readily available.
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We report a novel and highly selective electrochemical method for the synthesis of ß-iodoesters via difunctionalization of alkenes. The reaction is carried out in an undivided cell under constant current conditions without any additives, catalysts, oxidants, and sacrificial reagents. Inexpensive and readily available tetrabutylammonium iodide not only acts as an electrolyte but also serves as an iodine source. The reaction shows high selectivity and good functional group tolerance, providing products in yields of up to 98%. This method is applicable not only to the iodofunctionalization of alkenes but also to the chloro- and bromofunctionalization of alkenes. The successful modification of drugs and natural products demonstrates the potential utility of this approach.
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The paper details an electrochemical method that couples olefins with benzotriazoles to form C(sp2)-N bonds, enabling the synthesis of N-vinyl benzotriazoles in moderate to good yields. nBu4NI functions as both an electrolyte and an iodine mediator, and the method does not require oxidants or metals. It is a highly atom-economical and clean reaction, with hydrogen as the sole byproduct.
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We describe the enantioselective oxidative cross-coupling of secondary amines with ketones by combining the non-natural catalytic activity of lipase with electrosynthesis. Various 2,2-disubstituted 3-carbonyl indoles with a stereogenic quaternary carbon center were synthesized from 2-substituted indoles in yields up to 78 % with good enantio- and diastereoselectivities (up to 96 : 4 e.r. and >20 : 1 d.r.). This unprecedented protocol demonstrated that hydrolase catalysis is compatible with electrosynthesis, and the reaction can be carried out in organic solvents with a broad substrate scope and good stereoselectivity. This work provides insights into enzymatic electrosynthesis.
Assuntos
Aminas , Cetonas , Catálise , Indóis , Lipase , Estresse Oxidativo , EstereoisomerismoRESUMO
The electrochemical synthesis of 5-aminocoumaran derivatives from easily oxidizable aminophenols and readily available olefins is described. The reaction efficiently produces 5-aminocoumarans in high yield under mild and environmentally friendly conditions without the necessity of catalysts, additives, oxidizing agents, or sacrificial reagents. Hydrogen as the sole byproduct of the reaction makes the method clean, highly atom-efficient, and step-economical.
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OBJECTIVE: To investigate short-stage results of audiological change of nasopharyngeal carcinoma patients after radiotherapy and chemotherapy treatment. METHODS: According to treatment modus of nasopharyngeal carcinoma, 64 cases (128 ears) patients were divided to simple radiotherapy group (45 cases, 90 ears) and radiotherapy with chemotherapy group (combination treatment group, 19 cases, 38 ears). Meanwhile, 25 cases (50 ears) people took as control group, who had no obviously ear and nose disease. About two or three months after radiotherapy and chemotherapy treatment completion, three groups were detected by otoscopy, pure tone test, tympanogram and eustachian tube function, respectively. Then, hearing variation of all patients after radiotherapy and chemotherapy treatment were investigated and compared each other. At the same time, the character and level of audiological change were also analyzed. RESULTS: Eardrum character of nasopharyngeal carcinoma patients appeared change after radiotherapy. Simple radiotherapy and combination treatment groups were found having hearing impairment and eustachian tube functional disturbance. Moreover, most patients of simple radiotherapy group showed conductive deaf (24%, 22/90), and combination treatment group exhibited mingle (24%, 9/38) or sensorineural deafness (29%, 11/38). CONCLUSIONS: Recent hearing of nasopharyngeal carcinoma patients were damaged by radiotherapy and chemotherapy treatment, radiotherapy treatment induced middle ear or eustachian tube function disturbance, chemotherapy treatment had cochleotoxicity, compared with other treatment, combination treatment was more aggravated hearing impairment.