While a plethora of chemical transformations exists that utilize small-molecule catalysts, many of these reactions require the use of cocatalysts and consequently suffer from limitations of diffusion. To address this issue, it is proposed that single-chain polymer nanoparticles—folded polymers bound by intramolecular cross-links—be employed, as they provide the benefit of forcing cocatalysts into close proximity with one another through covalent linkage. Additionally, the confined environment provided by the supramolecular structure of an SCNP improves the catalytic efficiency of some transformations. A system utilizing a photoredox catalyst along with an electron relay cocatalyst is used as a model for demonstrating the utility of this technology. Additionally, the feasibility of developing such systems with modular attributes is illustrated by the preparation of a dipyrrin ligand designed for this purpose.
