Organocatalytic Reduction of Carbon-Carbon Double Bonds in Racemization-Sensitive Compounds

N-ethyl riboflavin efficiently catalyzes the hydrazine mediated reduction of carbon-carbon double bonds. This strategy allows chemo-selective, reductions in complex molecules that are prone to racemization, olefin isomerization, or hydrogenolysis in transition metal-catalyzed hydrogenations. The high functional group tolerance of this methodology is demonstrated as well.