Photochemical Synthesis of Chiral Heterocycles via Asymmetric Carbon-Heteroatom Bond Formation

Chiral heterocyclic compounds play a crucial role in the pharmaceutical science, materials science, and agrochemical industries. The critical step for synthesizing chiral heterocycles is the formation of asymmetric carbon-heteroatom bonds, which can be achieved in a chiral environment under thermal or photochemical conditions. However, photochemical asymmetric transformation has become an area of immense growth in the past 15 years. In the drug discovery and development era, chiral photochemical transformations have drawn the attention of researchers to develop new synthetic strategies for chiral heterocycles via asymmetric carbon-heteroatom bond formation. Chiral photochemistry in the pathway of asymmetric synthesis requires a chirality source which is transferred to the products. A catalytic chiral metal complexing agent or a chiral photosensitizer that generally follows a single electron transfer (SET) or oxidative and reductive quenching cycle has been widely exploited to achieve this goal. In this review, we have demonstrated the recent development of photochemical synthesis of chiral heterocycles via asymmetric carbon-heteroatom bond formation by using a chiral metal catalyst, asymmetric organocatalyst, or dual catalytic system based on their plausible mechanism. image