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Comprehensive Summary: A photoelectrochemical approach for the C—H silylation of heteroarenes through dehydrogenation cross‐coupling with H2 evolution has been developed. The photoelectrochemical C—H silylation depends on hydrogen atom transfer (HAT) from silanes to Cl‐radical generated through the light‐induced homolytic cleavage of Cl2, in which Cl2 was produced by electrochemical oxidation of chloride. A large number of silylated heterocyclic molecules are rapidly constructed in satisfactory yields without relying on oxidants and metal reagents. [ABSTRACT FROM AUTHOR]

An electrochemical electrophilic bromination/spirocyclization of N-benzyl-acrylamides with 2-bromoethan-1-ol as the brominating reagent has been developed. The paired electrolysis employs low concentrations of bromine produced from both cathodic reduction and anodic oxidation as an electrophile, and realizes an H2O-involved electrophilic spirocyclization. A number of unexplored brominated 2-azaspiro[4.5]decanes are obtained with satisfactory yields under mild conditions, and the reaction exhibits good efficiency at the gram-scale synthesis. In addition, this approach is further highlighted by late-stage transformations and synthetic applications in constructing cyclohepta[c]pyrrole-1,6-diones via debromination tandem cyclization of brominated 2-azaspiro[4.5]decanes. [ABSTRACT FROM AUTHOR]

C−H/N‐H cross‐coupling is an ideal strategy to synthesize various amines but remains challenging owing to the requirement for sacrificial chemical oxidants and the difficulty in controlling the regio‐ and chemo‐selectivity. Herein we report a site‐selective electrochemical amination reaction that can convert benzylic C−H bonds into C‐N linkages via H2 evolution without need for external oxidants or metal catalysts. The synthetic strategy involves anodic cleavage of benzylic C−H to form a carbocation intermediate, which is then trapped with an amine nucleophile leading to C−N bond formation. Key to the success is to include HFIP as a co‐solvent to modulate the oxidation potentials of the alkylbenzene substrate and the aminated product to avoid overoxidation of the latter. [ABSTRACT FROM AUTHOR]

A photoelectrochemical method for the C−H alkylation of heteroarenes with organotrifluoroborates has been developed. The merger of electrocatalysis and photoredox catalysis provides a chemical oxidant‐free approach for the generation and functionalization of alkyl radicals from organotrifluoroborates. A variety of heteroarenes were functionalized using primary, secondary, and tertiary alkyltrifluoroborates with excellent regio‐ and chemoselectivity. A radical approach: A photoelectrochemical method has been developed for the C−H alkylation of heteroarenes with organotrifluoroborates under oxidant‐free conditions. A variety of heteroarenes can be functionalized with primary, secondary, and tertiary alkyl groups with excellent regio‐ and chemoselectivity. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: A photoelectrochemical approach for the C—H silylation of heteroarenes through dehydrogenation cross‐coupling with H2 evolution has been developed. The photoelectrochemical C—H silylation depends on hydrogen atom transfer (HAT) from silanes to Cl‐radical generated through the light‐induced homolytic cleavage of Cl2, in which Cl2 was produced by electrochemical oxidation of chloride. A large number of silylated heterocyclic molecules are rapidly constructed in satisfactory yields without relying on oxidants and metal reagents. [ABSTRACT FROM AUTHOR]

Light and electric current power the C−H alkylation of heteroaromatics under oxidant‐free conditions. Organotrifluoroborates are converted into radicals that participate in intermolecular oxidative transformations without overoxidation to carbocations. As H.‐C. Xu and co‐workers describe in their Communication on page 4592 ff., this photoelectrochemical approach may provide a platform for further sustainable synthetic methodologies. [ABSTRACT FROM AUTHOR]