Executive Summary : | This proposal proposes the synthesis of covalent-organic cages using photoactive building units (diketopyrrolopyrrole and porphyrin) as photocatalysts and confined nanospace to host chemical transformations. These photoactive nanocages will be used for C-H bond oxidation reaction using molecular oxygen as an oxidant in confined space, mimicking enzyme reaction pockets. The starting material can be manipulated to access fused heterocyclic systems in mild conditions in one pot. Visible light photo-catalytic reactions have emerged as a green method, as activation occurs by absorption of light as the cleanest energy source. Organic photocatalysts have advantages such as nontoxicity, cheapness, strong absorption of visible light, more synthetic versatility, and finer tuning of redox properties. Porphyrins and metaloporphyrins dominate the field of photocatalysts, with diketopyrrolopyrrole (DPP) being an eminent donor-acceptor fluorophore and efficient light harvesting material. The combination of porphyrin and DPP in a distinct 3D architecture will retain individual properties and introduce a hydrophobic environment inside a cage cavity, making it an appealing synthetic host for photocatalytic synthesis of novel fused lactone-pyrrolidinone heterocycles in water using O2 as an oxidant. By rational engineering of DPP side chains, heterogeneous cages can be synthesized by grafting it on silica and reused. Fused lactone/pyrrolidinone framework is integral to the core structure of numerous natural products and non-natural compounds, covering a wide range of biological activities. However, the use of porphyrin-DPP containing distinct 3D covalent cage acting as a photocatalyst in environmentally benign solvent water has not yet been explored. |