Baeyer–Villiger oxidation

Baeyer–Villiger oxidation
Name	Baeyer–Villiger oxidation
Caption	General scheme of a ketone converted to an ester or lactone
Type	Oxidation, rearrangement
Catalyst	Peracids, peroxides, metal catalysts, organocatalysts
First reported	1899
Named after	Adolf von Baeyer; Victor Villiger

Baeyer–Villiger oxidation is an organic chemical transformation converting ketones into esters and cyclic ketones into lactones via insertion of an oxygen atom adjacent to a carbonyl. The reaction is widely used in Organic chemistry for functional group interconversion and ring expansion in syntheses associated with laboratories, universities, and industrial settings such as those run by BASF, Pfizer, and Merck & Co..

Introduction

The Baeyer–Villiger oxidation transforms a carbonyl-containing substrate into an oxygen-inserted product through an oxidative rearrangement mediated by peracids or peroxide-derived species. It is central to syntheses undertaken in institutions like Max Planck Society and California Institute of Technology and features in total syntheses published by groups at Harvard University, University of Cambridge, and University of Oxford. The transformation is named for chemists Adolf von Baeyer and Victor Villiger, and it has influenced methodologies in the organic programs of firms such as GlaxoSmithKline and Novartis.

Mechanism

The accepted mechanism proceeds through nucleophilic addition of a peracid or peroxy species to the carbonyl, forming a tetrahedral Criegee intermediate that undergoes concerted or stepwise rearrangement to deliver an ester or lactone and a carboxylic acid byproduct. Seminal mechanistic studies have been conducted by researchers affiliated with ETH Zurich, Columbia University, and Stanford University employing kinetics, isotopic labeling, and computational chemistry methods developed at institutions like Massachusetts Institute of Technology and Imperial College London. Key mechanistic concepts were advanced in work connected to Nobel laureates at Rockefeller University and theoretical studies at Princeton University.

Substrate Scope and Selectivity

The reaction tolerates aliphatic, aromatic, and heterocyclic ketones, giving esters or lactones whose regiochemistry depends on migratory aptitude of adjacent groups and electronic effects. Studies from research groups at University of California, Berkeley, Yale University, and Tokyo Institute of Technology have detailed migratory preferences, showing tertiary alkyl, aryl, and benzylic groups often migrate preferentially over primary alkyl groups. Substrate-controlled selectivity is exploited in syntheses reported in journals associated with editors at American Chemical Society and Wiley-VCH Verlag.

Reagents and Catalysts

Traditional reagents include peracetic acid and m-chloroperoxybenzoic acid (m-CPBA), reagents commonly procured from suppliers like Sigma-Aldrich and prepared following protocols developed at laboratories such as Scripps Research. Catalytic variants use transition metals (e.g., chromium, ruthenium, manganese), enzyme catalysts (Baeyer–Villiger monooxygenases from strains studied at University of Groningen), and organocatalysts advanced by groups at University of California, Los Angeles and University of Illinois Urbana–Champaign. Industrial processes in firms like Bayer and Dow Chemical Company employ peroxide-based oxidants and process-optimization strategies inspired by engineering groups at MIT.

Asymmetric Baeyer–Villiger Oxidation

Enantioselective versions employ chiral peracids, chiral Lewis acids, or engineered Baeyer–Villiger monooxygenases to introduce stereocenters in ester or lactone products. Breakthroughs in asymmetric catalysis have roots in laboratories led by figures associated with École Normale Supérieure, University of Tokyo, and prize-winning research connected to Wolf Prize and Tetrahedron Prize awardees. Industrial biocatalysis teams at Genentech and academic collaborations with European Molecular Biology Laboratory have optimized enzyme variants for preparative-scale asymmetric oxidations.

Synthetic Applications

The Baeyer–Villiger oxidation is applied in total syntheses of natural products and pharmaceuticals, enabling ring expansions and installation of ester functionalities in target molecules prepared by groups at Scripps Research, University of California, Santa Barbara, and Johns Hopkins University. Notable synthetic campaigns in which the transformation appears include routes to steroids, terpenes, and macrolides reported in collaboration with editorial boards of Nature Chemistry and Journal of the American Chemical Society. Process-scale implementations are reported from industrial R&D at AstraZeneca and pilot plants influenced by protocols from National Institute of Standards and Technology.

Historical Background

Adolf von Baeyer and Victor Villiger first reported the oxidation at the turn of the 20th century, work historically contextualized alongside contemporaneous advances by chemists in institutions such as University of Munich and University of Strasbourg. The reaction’s development intersected with growth of peracid chemistry influenced by laboratories in Paris and Zurich, and subsequent mechanistic and catalytic elaborations emerged from academic centers including Cambridge University and Columbia University through the 20th and 21st centuries.

Category:Organic reactions Category:Oxidation reactions