A greener pathway to enantiopurity: mechanochemical deracemization through abrasive grinding.

We report the first case of mechanochemical deracemization by using liquid-assisted abrasive grinding. The target molecule is a precursor of Paclobutrazol, an important fungicide and plant growth inhibitor. Using mechanochemical deracemization, we are even able to transform a 10% ee scalemic mixture of this latter in an enantioenriched product of 97% ee in a couple of hours. This is substantially shorter compared to solution-based deracemization methodologies. The present paper thus introduces an efficient and greener process to enantiopure material.