Ruthenium complexes, Noyori catalytic mechanisms

More recently Noyori developed asymmetric hydrogenation of simple ketones with BlNAP/diamine-ruthenium complexes.In this system the catalytic process contrasted with the conventional mechanism of asymmetric hydrogenation of unsaturated bonds which requires metal-substrate 7t-complexation. In fact with BlNAP/diamine-ruthenium neither the ketone substrate nor the alcohol product interacted with the metallic centre during the catalytic cycle. The enantiofaces of the prochiral ketones were differentiated on the molecular surface of the coordinatively saturated RuH intermediate. 

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