Mechanosynthesis of ruthenium trisbipyridyl complexes and application in photoredox catalysis in a ball-mill

Herein, we developed the mechanosynthesis of ruthenium trisbipyridyl complexes. Such complexes can be difficult to prepare in solution, with long reaction times and average yields. With ball-milling, less than 3.5 hours of milling were sufficient to obtain the complexes in high yield. Such complexes were then evaluated as catalysts in the light-promoted mechanochemical reductive dehalogenation reaction. In addition to working under solvent-less conditions, the use of a Hantzsch amide instead of the classical ester allowed to drastically simplify the purification of the final compounds.