Organic Photoredox-Catalyzed Cycloadditions under Single-Chain Polymer Confinement

Cooperative catalysis enables synthetic transformations that are not feasible using monocatalytic systems. Such reactions are often diffusion controlled and require multiple catalyst interactions at high dilution. We developed a confined dual-catalytic polymer nanoreactor that enforces catalyst colocalization to enhance reactivity in a fully homogeneous system. The photoredox-catalyzed dimerization of substituted styrenes is disclosed using confined-single-chain polymers bearing triarylpyrylium-based pendants, with pyrene as an electron relay catalyst. Enhanced reactivity with low catalyst loadings was observed compared to monocatalytic polymers with small-molecule additives and analogous small molecules. Our approach realizes a dual-catalytic single-chain polymer that provides enhanced reactivity under confinement, presenting a further approach for diffusion-limited-photoredox catalysis.