An evolved artificial radical cyclase enables the construction of bicyclic terpenoid scaffolds via an H-atom transfer pathway

Although natural terpenoid cyclases generate polycyclic structures through cationic intermediates, alternative radical cyclization pathways are underexplored. Now an artificial radical cyclase has been prepared by anchoring a biotinylated cobalt Schiff-base complex within a chimeric streptavidin scaffold. Chemogenetic optimization of the catalytic performance affords enantioenriched terpenoids via a metal-catalysed H-atom transfer mechanism.