Executive Summary : | This project aims to develop visible-light energy transfer (EnT) catalysis for novel dearomative cycloaddition and diverse bond formation reactions under mild and environment-friendly conditions. A suitable photosensitizer (PS) will absorb visible light and transfer it to a non-absorbing substrate via an intermolecular EnT mechanism. The generated excited state of the substrate will be involved in facile step-wise bond formation reactions. The project systematically studies intra- and intermolecular cycloaddition for a diverse range of abundant 2D aromatic feedstock to create a diverse library of sp3-rich rigid saturated cyclic molecules. The modular nature of the reaction design, choice of appropriate PS, and proper reaction conditions allow subtle control over regio- and stereoselectivity. This approach could solve the poor product yield, reversibility, and functional group tolerance issues in traditional thermal and high-energy ultraviolet light-mediated protocols. The project also focuses on developing an eccentric pathway regarding photoredox/transition metal dual catalysis for cross-coupling reactions. The proposed process leverages the visible light's energy to trigger small molecule activation, enabling chemical bond formation via oxidative, reductive, and triplet EnT processes. Sustainable visible-light energy can be employed in a full-fledged manner to design new energy transfer and redox catalysts. Successful implementation of this idea will pave the way for long-term visible light energy-driven alterations of bioactive compounds and natural products. The knowledge gained from this systematic study will allow novel reaction designs employing visible-light energy sensitization and open up broader possibilities for research into this chemical arena. |