An electrochemical direct ortho‐hydroxylation of 2‐aryl‐4H‐benzo[e][1,3]oxazin‐4‐ones was developed with Pd(OAc)2 as catalyst, oxazine ring as a directing group and Oxone as the hydroxylation reagent. A series of hydroxylation products were obtained under mild conditions, and the yields were from medium to good. This method is characterized by good functional group tolerance and a wide range of substrates. More importantly, use anodic oxidation to avoid the use of potentially toxic and polluting oxidants. A gram‐scale direct electrochemical hydroxylation of 2‐phenyl‐4H‐benzo[e][1,3]oxazin‐4‐one was performed, and the hydroxylation product was applied to synthesize the drug deferasirox. In addition, the single crystal of 2‐(2‐hydroxyphenyl)‐4H‐benzo[e][1,3]oxazin‐4‐one was obtained and determined by X‐ray diffraction. Finally, the reaction mechanism was proposed and verified by cyclic voltammetry (CV). This protocol also provides an alternative electrochemical hydroxylation methodology for the functionalization of molecules.
An effective method for the synthesis of benzazoles through the electrochemical oxidative cyclization of o-aminophenol/oaminothiophenol/o-phenylenediamine and aldehydes was developed. A series of benzazoles were efficiently synthesized by using this method in good yields. Furthermore, this method was applied to the synthesis of the drug thiabendazole in a gram-scale reaction, which proved the practicality of the method. This approach avoids using catalysts and oxidants, and has the advantages of wide substrate range, mild reaction conditions and good tolerance of functional groups. Finally, the possible reaction mechanism was proposed and supported by cyclic voltammetry (CV) and control experiments.
A visible light-induced photocatalytic strategy for synthesis of flavonoids was developed through deoxygenative/cyclization reaction of salicylic acid derivatives with aryl acetylene by diphenyl sulfide as an O-transfer reagent. Based on...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.