The implementation of continuous flow technology is critical towards enhancing the application of photochemical reactions for industrial process development. However, there are significant time and resource constraints associated with translating discovery scale vial-based batch reactions to continuous flow scale-up conditions. Herein we report the development of a droplet microfluidic platform, which enables high-throughput reaction discovery in flow to generate pharmaceutically relevant compound libraries. This platform allows for enhanced material efficiency, as reactions can be performed on picomole scale. Furthermore, high-throughput data collection via on-line ESI mass spectrometry facilitates the rapid analysis of individual, nanoliter-sized reaction droplets at acquisition rates of 0.3 samples/s. We envision this high-throughput screening platform to expand upon the robust capabilities and impact of photochemical reactions in drug discovery and development.

A net redox-neutral method for the decarboxylative alkylation of heteroarenes using photoredox catalysis is reported. Additionally, this method features the use of simple, commercially available carboxylic acid derivatives as alkylating agents, enabling the facile alkylation of a variety of biologically relevant heterocyclic scaffolds under mild conditions.

The Minisci reaction, which encompasses the radical C–H alkylation of heteroarenes, has undergone revolutionary development in recent years. The application of photoredox catalysis to alkyl radical generation has given rise to a multitude of methods that feature enhanced functional group tolerance, generality, and operational simplicity. The intent of this short review is to bring readers up to date on this rapidly expanding field. Specifically, we will highlight key examples of visible-light-driven Minisci alkylation strategies that represent key advancements in this area of research. The scope and limitations of these transformations will be discussed, with a focus on examining the underlying pathways for alkyl radical generation. Our goal is to make this short review a stepping stone for further synthetic research development. Sections are organized based on alkyl radical precursor reagents.1 Introduction2 Alkyl Carboxylic Acids and Carboxylic Acid Derivatives3 Alkylboronic Acids4 Potassium Alkyl- and Alkoxymethyltrifluoroborates5 Alkyl Halides6 Alcohols and Ethers7 Conclusion

Adenosine triphosphate (ATP) provides the driving force necessary for critical biological functions in all living organisms. In synthetic biocatalytic reactions, this cofactor is recycled in situ using high-energy stoichiometric reagents, an approach that generates waste and poses challenges with enzyme stability. On the other hand, an electrochemical recycling system would use electrons as a convenient source of energy. We report a method that uses electricity to turn over enzymes for ATP generation in a simplified cellular respiration mimic. The method is simple, robust, and scalable, as well as broadly applicable to complex enzymatic processes including a four-enzyme biocatalytic cascade in the synthesis of the antiviral molnupiravir.

We report a rapid, one-pot, operationally simple, and scalable preparation of valuable cationic heteroleptic iridium(III) polypyridyl photosensitizers. This method takes advantage of two consecutive microwave irradiation steps in the same reactor vial, avoiding the need for additional reaction purifications. A number of known heteroleptic iridium(III) complexes are prepared in up to 96% yield. Notably, this method is demonstrated to provide the synthetically versatile photosensitizer [Ir(ppy)2(dtbbpy)]PF6 in >1 g quantities in less than 5 h of bench time. We envision this method will help accelerate future developments in visible-light-dependent chemistry.