Comprehensive and in-depth insights into photo-assisted halogenation reactions: a pharmaceutical industry perspective

Abstract Halogenation reactions are a vital area of study for the pharmaceutical industry. The study of the reaction conditions along with the reactors and their scale-up is a thrust area in drug synthesis and manufacturing. There is a shift in the research community towards accommodating renewable energy sources which has driven scientists to include energy sources that are sustainable and aid in making the overall process efficient. This review provides a comprehensive overview of the challenges in selecting the best catalyst, light source and reaction conditions for the fluorination, chlorination and bromination reactions. This paper goes a step further to explain the photoreactors’ design and modelling as well as the scale-up of the same. Overall, it provides a comprehensive view of diverse scientific areas, from halogenation in drug synthesis to the potential of photochemical batch and flow approaches in halogenation reactions.