Photobiocatalytic Strategies for Organic Synthesis

Abstract

Biocatalysis has revolutionized chemical synthesis, providing sustainable methods for preparing various organic molecules. In enzyme-mediated organic synthesis, most reactions involve molecules operating from their ground states. Over the past 25 years, there has been an increased interest in enzymatic processes that utilize electronically excited states accessed through photoexcitation. These photobiocatalytic processes involve a diverse array of reaction mechanisms that are complementary to one another. This comprehensive review will describe the state-of-the-art strategies in photobiocatalysis for organic synthesis until December 2022. Apart from reviewing the relevant literature, a central goal of this review is to delineate the mechanistic differences between the general strategies employed in the field. We will organize this review based on the relationship between the photochemical step and the enzymatic transformations. The review will include mechanistic studies, substrate scopes, and protein optimization strategies. By clearly defining mechanisticallydistinct strategies in photobiocatalytic chemistry, we hope to illuminate future synthetic opportunities in the area.

Recent Advances in Visible Light‐induced Asymmetric Transformations of Carbonyl Compounds into Chiral Alcohols

“…Biocatalytic photosynthesis merging the biocatalysis and photocatalysis has become of great interest in the field of synthetic chemistry. [87][88][89][90][91] In 2019, the Hyster group exploited this strategy to realize the enantioselective reduction of ketones through a combination of an ene-reductase and a ruthenium photocatalyst (Scheme 24). [92] This transformation is found to be compatible with diaryl and aryl alkyl ketones, affording chiral alcohols in moderate to good yields with moderate enantioselectivities.…”

Synthetic Approaches to the Challenging Direct C‐Alkylation and C‐Allylation of Unactivated Nitroalkanes

“…The new frontier for the assembling of molecular frameworks entails the utilization of photobiocatalytic strategies. [79] The first asymmetric photoenzymatic catalyzed procedure for the reaction of nitroalkanes with α-chloroamides has been realized very recently using a flavin-dependent 'ene'-reductase (ERED) jointly with cyan LED irradiation. [80] The alkylation was successfully carried out but the nitro group was contextually eliminated as nitrite anion leading to the formation of enantioenriched alkylated amides.…”

Highly Efficient Nitrogen‐Fixing Microbial Hydrogel Device for Sustainable Solar Hydrogen Production

“…[6,7] Solar fuel synthesis using microbial systems, [8][9][10] in particular, is a vital emerging approach to environmentally sustainable solar energy conversion [11][12][13] due to its high selectivity, [14] feasibility, [15] and durability. [16,17] Efficient lab-scale microbial fuel production, [18][19][20] including microbial solar hydrogen (H 2 ) production, [21,22] has been achieved by recent research efforts such as advanced genetic engineering [23][24][25] and incorporation of semiconductor biohybrids. [26,27] However, the practical use of conventional microbial fuel production systems has been impeded, primarily by system-level design challenges such as ineffective supply of reactants and capture of products [28,29] as well as by the requirement of electrodes [30,31] and scale-up issues.…”