Synthesis of N-heterocycles from diamines via H2-driven NADPH recycling in the presence of O2†
Herein, we report an enzymatic cascade involving an oxidase, an imine reductase and a hydrogenase for the H2-driven synthesis of N-heterocycles. Variants of putrescine oxidase from Rhodococcus erythropolis with improved activity were identified. Substituted pyrrolidines and piperidines were obtained with up to 97% product formation in a one-pot reaction directly from the corresponding diamine substrates. The formation of up to 93% ee gave insights into the specificity and selectivity of the putrescine oxidase.