Reaching the Pinnacle: S-Metolachlor and the Largest Industrial-Scale Enantioselective Chemical Process Ever Developed

(S)-metolachlor, the active ingredient of the Dual Magnum herbicide, is prepared industrially via an Iridium-Xyliphos -catalysed enantioselective hydrogenation reaction. This process, first run at production scale in 1996, is the world’s largest application of a single catalytic asymmetric reaction to date. In excess of 10,000 tons per year of enantioenriched amine intermediate are produced via reduction of an imine precursor (N-(2-ethyl- 6-methylphenyl)-1-methoxypropan-2-imine -MEA imine).

The catalyst is tuned to perfection- with turnover frequencies (TOFs) exceeding 1.8×10⁶ h^-1 and turnover numbers (TONs) exceeding 2×10⁶.Not surprisingly very detailed optimisation and extensive process understanding were important aspects in the development cycle.

This webinar looked at the journey from early reaction screening and development to an established manufacture process, highlighting general issues involved in developing large scale catalytic processes. Welcome to the greatest show on Earth!

The webinar was presented by Dr John Studley, Scientific Update