Catalytic hydrogenation of ketones and imines

This was developed for Syngenta and was a landmark product for enantioselective industrial catalytic synthesis. The full story behind this remarkable piece of work has been reported by Blaser. Catalyst turnover numbers of 2000000 and turnover frequency values of around 600 000 h allow highly efficient production of this important intermediate maize crop herbicide (Dual Magnum ).  

Catalysts for ketone hydrogenation continue to be developed but one of the best systems is still the BINAP-DPEN catalyst first reported by Ohkuma et al. in 1995. In this system ruthenium is combined with both a chiral diphosphine and a chiral diamine, forming an octahedral complex which gives a high degree of enantioselectivity. This stereoselectivity is considered to be a result of the synergistic effect of the chiral diphosphine and diamine ligands. 

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