Photocatalytic Aerobic Amine Oxidation: Use of Water for Designing a Circular Photosynthetic Strategy

The design of industrially relevant synthetic methodologies is expected to aim for circularity—commonly indicated by the upcycling or recycling of reagents/catalysts/solvents and minimizing the waste generated while ensuring complete or stoichiometrically relevant conversions. This demanding set of criteria makes the attainment of circularity very challenging. The present article aims toward achieving near‐circularity in the form of a facile photosynthetic strategy utilizing dye‐TiO 2 system in water with visible light activation and air oxidation for highly selective amine oxidation. Control experiments provide critical insights in to the role of water when used as a reaction medium. Selective conversion imines, facile yields, recyclability of the catalyst, and demonstrated scalability are all instrumental for achieving circularity. The present article is a proof‐of‐concept that water can be a critical component for incorporating circularity in the synthetic protocol.