Nonconventional regeneration of redox enzymes – a practical approach for organic synthesis?

Abstract

Oxidoreductases have become useful tools in the hands of chemists to perform selective and mild oxidation and reduction reactions. Instead of mimicking native catalytic cycles, generally involving costly and unstable nicotinamide cofactors, more direct, NAD(P)-independent methodologies are being developed. The promise of these approaches not only lies with simpler and cheaper reaction schemes but also with higher selectivity as compared to whole cell approaches and their mimics.

Two-Component FAD-Dependent Monooxygenases: Current Knowledge and Biotechnological Opportunities

“…Therefore, alternative cofactor regeneration systems have been developed for group E monooxygenases, including the direct regeneration by an organometallic catalyst, electrochemical approaches and the use of cofactor mimics [ 135 , 180 ]. Usability in a biocatalytic process has already been shown in liquid two-phase systems [ 181 , 182 , 183 ] and was transferred into large and pilot scale [ 30 , 184 ].…”

Photoenzymatic epoxidation of styrenes

“…Instead, direct photochemical regeneration of reduced enzyme prosthetic groups is gaining increasing attention. 23,24 We therefore set out to explore the possibility of direct, photocatalytic regeneration of FADH 2 to promote StyA-catalysed epoxidations of styrene and its derivatives (Scheme 1, bottom). Very recently, Kottke and coworkers reported the successful application of this approach to promote a 2CDFM-driven halogenation reaction.…”

H2as a fuel for flavin- and H2O2-dependent biocatalytic reactions

“…Mimicries of the natural, NAD(P)H-dependent regeneration pathways are currently the most widely used approach, but suffer from complex reaction schemes, the need for the nicotinamide cofactor and the formation of significant wastes originating from stoichiometric reductants such as glucose. 3 In addition, some photo 4 and electrochemical 5,6 approaches to regenerate reduced flavins have been reported.…”