The exquisite chemoselectivity and the intrinsic compatibility of enzymes have been widely exploited during the past decade for the development of multi-step biocatalytic reactions in one-pot. In this context, hydrogen-borrowing cascades permit to maximise the atom-efficiency through the internal recycling of redox equivalents, which avoids the use of additional oxidants or reductants. Here, we describe the state-of-the-art in the field of biocatalytic hydrogen-borrowing cascades and provide a future perspective for a wider implementation in organic synthesis.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5837015 | PMC |
Angew Chem Int Ed Engl
January 2025
University of Oxford, Chemistry, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.
The catalytic action of enzymes of a cascade trapped within a mesoporous electrode material is simultaneously energized, controlled and observed through the efficient, reversible electrochemical NAD(P)(H) recycling catalyzed by one of the enzymes. In their nanoconfined state, nicotinamide cofactors are tightly channeled current carriers, mediating multi-step reactions in either direction (oxidation or reduction) with a rapid response time. By incorporating a hydrogen‑borrowing enzyme pair, the internal action of which opposes the external voltage bias driving oxidation or reduction, a reduction process can be performed under overall oxidizing conditions, and vice versa.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, UK.
Compounds containing quaternary stereocentres are a valuable motif in biologically active compounds. Herein we present our strategy to utilise the hydrogen borrowing manifold to access α-quaternary ketones via a tandem acceptorless dehydrogenation-cyclisation cascade. This new application of the methodology results in the formation of five- and six-membered carbocycles with a high degree of diastereoselectivity.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
November 2024
Laboratory of Biocatalysis and Biotransformation, Department of Drugs Technology and Biotechnology, Faculty of Chemistry, Warsaw University of Technology, Koszykowa 75, 00-662, Warsaw, Poland.
Dynamic kinetic resolution (DKR) is a key method used to prepare optically pure compounds in 100 % theoretical yield starting from racemic substrates by combining the interconversion of substrate enantiomers with an enantioselective transformation. Various chemoenzymatic DKR approaches have been developed to deracemize secondary alcohols, typically requiring an organic solvent to facilitate enantioselective acylation, primarily catalyzed by lipases, alongside racemization mediated by an achiral, non-enzymatic catalyst. Achieving both steps in an aqueous solution remained elusive.
View Article and Find Full Text PDFJ Agric Food Chem
November 2024
State Key Laboratory of Bioreactor Engineering, New World Institute of Biotechnology, East China University of Science and Technology, Shanghai 200237, China.
()-Citronellal is a key chiral precursor of high-value chemicals, such as the best-selling flavor compound (-)-menthol; however, the conventional synthesis suffers from low yield and unsatisfactory enantioselectivity. In this study, we developed a highly atom-efficient hydrogen-borrowing cascade for the synthesis of ()-citronellal from geraniol using alcohol dehydrogenase from K12 (AdhP) and ene-reductase from YJM1341 (OYE2p). The key rate-limiting enzyme, AdhP, was subjected to structure-guided semirational engineering, and the triple mutant AdhP (M3) was obtained that demonstrated a 1.
View Article and Find Full Text PDFJ Org Chem
September 2024
Key Laboratory of Chemistry in Ethnic Medicinal Resources and Key Laboratory of Natural Products Synthetic Biology of Ethnic Medicinal Endophytes, School of Ethnic Medicine, Yunnan Minzu University, Kunming 650500, China.
A novel electrocatalytic dimerization of -aminphenols and a hydrogen borrowing-like cascade for synthesizing N-monoalkylated aminophenoxazinones have been developed. This electrocatalytic reaction uses a constant current mode in an undivided cell and is free of metal catalysis, open to the air, and eco-friendly. In particular, this protocol exhibits a wide substrate range and provides versatile N-monoalkylated aminophenoxazinones in medium to good yields.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!