A regenerable immobilized NADH model. Reduction of α,α,α-trifluoroacetophenone by 1, 4-dihydronicotinamide anchored to macroreticular polystyrene

A regenerable dihydronicotinamide immobilized on a macroreticular polystyrene carrier was developed and used in an aqueous medium for the reduction of trifluoroacetophenone to the corresponding alcohol. It was shown that the second-order rate constant for the polymer-bound reagent is significantly lower than that of the low-molecular-weight analog 1-benzyldihydronicotinamide. The observed reaction rate, however, was of the same order of magnitude as that due to enrichment of substrate in the polymeric pores. It was possible to depress the undesired side reactions to 10–15% per reaction cycle, thereby allowing reutilization of the functionalized polymer.