Batch and Continuous-Flow Electrochemical Geminal Difluorination of Indeno[1,2-c]furans.

An electrochemical gem-difluorination of indeno[1,2-c]furans using commercially available and easy-to-use triethylamine trihydrofluoride as both the electrolyte and fluorinating agent was developed. Remarkably, different reaction pathways of indeno[1,2-c]furans, i.e., paired electrolysis and net oxidation, are operative in a batch reactor and a continuous-flow microreactor to afford the corresponding gem-difluorinated indanones and indenones, respectively.

Synthesis of Indeno[1,2-c]furans via Cobalt-Catalyzed Radical-Polar Crossover [3 + 2] Cycloaddition of o-Alkynylaryl ß-Dicarbonyls.

Fused polycyclic furans are privileged structural scaffolds in materials chemistry, including organic semiconductors. Specifically, indeno[1,2-c]furans are an interesting type of polycyclic furans featuring a fused furan and indenone framework. Unfortunately, limited studies on their photophysical properties have been performed, probably owing to the lack of efficient and straightforward approaches to those compounds. Herein, we have developed a cobalt-catalyzed radical-polar crossover cyclization of the readily available o-alkynylaryl ß-carbonyls to afford diverse indeno[1,2-c]furans. Photophysical and DFT calculations were also carried out, suggesting that the obtained indeno[1,2-c]furans exhibit promising electronic and optical properties.

Cobalt-Catalyzed Divergent Aminofluorination and Diamination of Styrenes with N-Fluorosulfonamides.

A cobalt-catalyzed aminofluorination reaction of styrenes with N-fluorosulfonamides serving as both the amination and fluorination agents has been developed. The switch of selectivity in this catalytic reaction from aminofluorination to diamination could be easily achieved by the addition of 1.0 equiv of PPh3. Both transformations tolerated a wide array of substrates under mild reaction conditions.