COFcap2, a recyclable tandem catalysis reactor for nitrogen fixation and conversion to chiral amines.

Two or more catalysts conducting multistep reactions in the same reactor, concurrent tandem catalysis, could enable (bio)pharmaceutical and fine chemical manufacturing to become much more sustainable. Herein we report that co-immobilization of metal nanoparticles and a biocatalytic system within a synthetic covalent organic framework capsule, COFcap-2, functions like an artificial cell in that, whereas the catalysts are trapped within 300-400 nm cavities, substrates/products can ingress/egress through ca. 2 nm windows. The COFcap-2 reactor is first coated onto an electrode surface and then used to prepare eleven homochiral amines using dinitrogen as a feedstock. The amines, including drug product intermediates and active pharmaceutical ingredient, are prepared in >99% enantiomeric excess under ambient conditions in water. Importantly, the COFcap-2 system is recycled 15 times with retention of performance, addressing the relative instability and poor recyclability of enzymes that has hindered their broad implementation for energy-efficient, low waste production of chemicals and (bio)pharmaceuticals.