Executive Summary : | Nitrogen heterocycles, which make up over 60% of all medicinal ingredients, are crucial in the pharmaceutical and agrochemical sectors for the development of modern drugs against various pathological conditions. Conventional approaches to synthesize these heterocycles face challenges such as harsh conditions, long reaction times, expensive starting materials, and low reaction yields. The development of more sustainable, mild, and environmentally benign approaches is highly desirable. Visible light-induced organic transformations have emerged as an alternative to traditional methods due to their benign reaction conditions. Visible light-induced electron donor acceptor (EDA) complex-driven synthetic methods have gained popularity as they don't require expensive and elaborative photocatalysts. This proposal aims to generate aminoalkyl radicals from NHPI esters through EDA mechanisms under visible light irradiation and react them with suitable π-radical acceptors in radical cascade annulations to afford substituted nitrogen heterocycles of pharmaceutical importance. This green chemistry approach is efficient and intriguing for producing fused/spiro N-heterocycles. The proposed reaction pathway is activated by the formation of an EDA complex between a NHPI ester and a suitable donor to generate α-amino radicals under visible light irradiation. The annulation of generated alkyl radicals with these acceptors should result in the formation of desired heterocycles. |