Catalytic Oxygenation Strategies in Organic Synthesis

Catalytic oxygenation represents a cornerstone of modern organic synthesis, enabling the direct installation of oxygen functionalities into a wide array of substrates with high levels of chemo-, regio- and stereocontrol. Central transformations include epoxidation of alkenes, dihydroxylation to generate vicinal diols, and direct C–H oxygenation via cross-dehydrogenative coupling. Advances in catalyst design—ranging from transition-metal complexes to organocatalysts and hypervalent iodine reagents—have driven improvements in selectivity, operational simplicity and sustainability. Mechanistic diversity spans ionic pathways, such as oxygen transfer from metal–oxo species, to radical-mediated processes employing N-oxyl intermediates. Emerging green protocols exploit benign oxidants such as hydrogen peroxide or molecular oxygen, minimising waste and toxic by-products. These strategies underpin the synthesis of pharmaceuticals, agrochemicals and fine chemicals, reflecting their global significance. Interconnections between asymmetric epoxidation/dihydroxylation and direct C–H functionalisation illustrate a unified aim: to achieve efficient, selective oxygen incorporation under ever milder and more environmentally friendly conditions.

Research from Nature Portfolio

Recent studies have developed a chiral molybdenum–bishydroxamic acid catalyst that achieves highly enantio- and diastereoselective anti-dihydroxylation of allylic alcohols using hydrogen peroxide. The protocol proceeds via an initial enantioselective epoxidation followed by in situ regioselective ring-opening, enabling construction of 1,2,3-triols with precise stereocontrol and complementing established syn-dihydroxylation methods. In parallel, an iodine(III) methodology employing iodobenzene diacetate and N-hydroxyphthalimide has realised cross-dehydrogenative C–O coupling with unactivated C(sp3)–H bonds. This metal-free process generates phthalimide-N-oxyl radicals that engage in direct C–H activation under mild conditions, affording O-functionalised derivatives in good yields and broad substrate scope.

Catalytic Oxygenation Strategies in Organic Synthesis publication trend

The graph below shows the total number of articles in catalytic oxygenation strategies in organic synthesis across all publications each year (not limited to Nature Index journals).

Technical terms

Catalytic Oxygenation: Introduction of oxygen into organic substrates facilitated by a catalyst under controlled conditions.

Dihydroxylation: Addition of two hydroxyl groups (–OH) across a carbon–carbon double bond.

Epoxidation: Conversion of an alkene to an epoxide (three-membered cyclic ether) by an oxygen transfer.

Cross-dehydrogenative Coupling: Direct formation of a new bond between two substrates via concurrent removal of hydrogen atoms, avoiding pre-functionalisation.

Hypervalent Iodine Reagents: Iodine species in oxidation states higher than +1, used as mild, selective oxidants in organic synthesis.

N-Oxyl Radicals: Nitrogen-centred radicals derived from N-hydroxy compounds, often used to mediate oxygen transfer or C–H activation.

References

1. anti -Dihydroxylation of olefins enabled by in situ generated peroxyacetic acid. Green Chemistry (2024).
2. Hypervalent iodine compounds for anti-Markovnikov-type iodo-oxyimidation of vinylarenes. Beilstein Journal of Organic Chemistry (2018).
3. Molybdenum-catalyzed asymmetric anti-dihydroxylation of allylic alcohols. Communications Chemistry (2019).
4. Iodine(III) promotes cross-dehydrogenative coupling of N-hydroxyphthalimide and unactivated C(sp3)–H bonds. Communications Chemistry (2021).