Chiral heterogeneous photocatalysts for enantioselective synthesis: standing on the shoulders of organocatalysis.

Crafting organic molecules with control over their absolute stereochemistry is a challenging task for synthetic chemists. The present Perspective encompasses recent examples of enantioselective transformations based on chiral heterogeneous photocatalysts, including metal-organic frameworks (MOFs), covalent organic frameworks (COFs) and hybrid metal-halide perovskites (MHPs). Such materials combine a photocatalytic unit and a chiral element in a single component: the former is responsible for substrate activation, while the latter, typically a small organic molecule - i.e., an organocatalyst -, takes care of stereoinduction instead. Although synthetic applications are still limited to a handful of (benchmark) C-C and C-N bond formations and oxidation protocols, their number is expected to grow steadily in the near future. This trend is supported by cross-disciplinary knowledge transfer from the field of asymmetric organocatalysis, which is also driving the application of these materials in broader areas, such as solar-to-chemical energy conversion and chiral sensing technologies.