An environmentally friendly electrochemical process for the direct trifluoromethylation of 2-pyridones with a broad substrate scope has been developed.

Water soluble biomimetic models of Riboflavin (B2 vitamin) and Folic acid (B8 vitamin) demonstrated to be good oxidant of formic acid at various pH. Their usage as anolyte mediators in a flow fuel cell to convert formic acid (or formate) into electricity is validated with measured power densities up to 16 mW.cm− 2. These preliminary optimum conditions demonstrated a volumetric energy density of 0.68 Wh.L− 1 when operating at 5 mA.cm− 2 and neutral pH. These new conditions inspired from redox flow batteries processes permit to remove noble metals at both sides of the formate flow fuel cell.

An efficient and versatile protocol for the C-H sulfonylation of imidazoheterocycles via electrochemical activation was established under batch and flow conditions. The selective C-H bond functionalization proceeded under catalyst- and oxidant-free conditions and tolerated a wide range of functional groups. Various sodium sulfinates as well as imidazo[1,2-a]-pyridines, -pyrimidine, -quinolines, and -isoquinolines, imidazo[1,2-b]pyridazine, imidazo[2,1-b]thiazoles and benzo[d]imidazo[1,2-b]thiazoles reacted successfully. Interestingly, significant acceleration and higher yields were obtained under microfluidic conditions.

With the depletion of fossil-fuel-based energies and the corresponding growing environmental concerns, the design of new strategies to store renewable solar energy is highly attractive. Herein, we studied a biomimetic organic solar fuel (Riboflavin - Vitamin B2) to photochemically store solar light into its amphoteric form (leucodeuteroflavin), working as a charge carrier towards a flow fuel cell. We demonstrate that miniaturization of the photoreactor permits significant reduction of the full time solar charge. Nevertheless, due to inherent leucodeuteroflavin (LDH2) degradation into lumichrome (LC), the maximum system charge (at pH=5) is limited to 13 % corresponding to a maximum power density of 0.11 mW cm(-2) after 90 min. In comparison with other described photoredox electroactive systems (e. g. polyoxometalates, quinones), organic solar fuels based on flavins appear particularly promising and their chemical structure should be optimized to fit both photostability and economical requirements. In any case, this study enables a clear rationalization and quantification of the mechanism of riboflavin degradation under anaerobic conditions, which has been the topic of many discussions during the last century, and opens the way towards the development of a new generation of low-cost renewable organic solar fuels.