Cascade Biotransformation to Access 3‐Methylpiperidine in Whole Cells

Abstract Synthesis of 3‐methylpiperidine from 1,5‐diamino‐2‐methylpentane in preparative scale is reported by using recombinant Escherichia coli cells expressing a variant of the diamine oxidase from Rhodococcus erythroprolis and an imine reductase from Streptosporangium roseum . Optimization of process parameters for cultivation and bioconversion led to substantial improvements in the initial laboratory procedure. The transformation of the methyl‐substituted diamine substrate to the N ‐heterocyclic product was successfully scaled‐up from shake‐flask to a 20 L bioreactor with increased substrate concentrations. Remarkably, we obtained 67 % of 3‐methylpiperidine product from 140 g substrate within 52 h.