Biooxidations in Chiral Synthesis

2,5-Diketopiperazine Catalysts as Activators of Dioxygen in Oxidative Processes

“…Selective oxidations, as exemplified by the power of monooxygenase in nature, are in the constant focus of the scientific community . Monooxygenases are among the most versatile enzymes of life, performing a wide range of oxidations, including the challenging oxidation of unreactive C–H bonds . The reaction proceeds through an electron-transfer chain, which ultimately leads to the activation of dioxygen that serves as the terminal oxidant of the process.…”

Enantioselective Oxidation of C–O and C–N Bonds Using Oxidases

“…Increasingly, however, attention and effort are being devoted to the development of mild, selective, and catalytic processes for effecting these transformations, including the use of organocatalytic methods . In this respect, enzymes also offer a potential solution, not only because of the exquisite selectivity, mild reaction conditions, and high rates of turnover that can be obtained but also because there are a truly diverse range of different enzyme types that catalyze oxidation reactions (Figure ). − Enzymes are able to catalyze oxidation processes encompassing hydroxylation and dihydroxylation of both aliphatic and aromatic C–H bonds, epoxidation, heteroatom oxidation including sulfoxidation and amine oxidation, Baeyer–Villiger oxidation of ketones to lactones, and halohydrin formation from alkenes. In many cases, enzymes are able to activate unactivated C–H and CC bonds and hence often provide access to products that would be difficult, if not impossible, to obtain in a single step using alternative nonbiocatalytic processes.…”