Photocatalytic Isomerization of Olefins

Photocatalytic isomerization of olefins harnesses light energy to reversibly convert carbon–carbon double bonds between geometrical E and Z configurations. This approach transcends the limitations of thermal control by using visible or near-UV photons to access excited states that facilitate selective bond rotation or migration. Through judicious selection of photocatalysts and sensitizers, researchers can achieve contra-thermodynamic products under mild conditions, often with high stereoselectivity and functional-group tolerance. Such processes have found applications in fine-chemical synthesis, natural-product modification and the generation of stereochemically defined intermediates for pharmaceuticals. The interplay of energy-transfer and electron-transfer pathways, coupled with catalyst design, underpins advances in reaction scope, efficiency and sustainability.

Research from Nature Portfolio

A recent advance has revealed a dinuclear palladium(I) complex that mediates E to Z isomerization of 1,3-dienes without external irradiation. By orchestrating sequential dinuclear elementary steps, the system kinetically traps the Z-isomer through shared catalytic intermediates, effectively injecting chemical energy from a conjugate reaction. This strategy bypasses the need for photonic input and demonstrates a novel paradigm in geometric control, highlighting how organometallic frameworks can emulate photocatalytic selectivity in the dark.

Photocatalytic Isomerization of Olefins publication trend

The graph below shows the total number of articles in photocatalytic isomerization of olefins across all publications each year (not limited to Nature Index journals).

Technical terms

Olefin: A hydrocarbon containing at least one carbon–carbon double bond, also known as an alkene.

Photocatalyst: A substance that absorbs light to initiate or accelerate a chemical reaction without being consumed.

Photosensitiser: A molecule that transfers energy from an excited state to a substrate, enabling photochemical transformations.

E/Z isomerisation: The conversion between two stereoisomers of an alkene distinguished by the relative positions of substituents across the double bond.

Energy transfer catalysis: A mechanism in which an excited-state catalyst transfers electronic energy to a substrate, promoting selective bond rearrangements.

References

1. Selective E to Z isomerization of 1,3-Dienes Enabled by A Dinuclear Mechanism. Nature Communications (2021).
2. Merging Grubbs second-generation catalyst with photocatalysis enables Z -selective metathesis of olefins: scope, limitations, and mechanism. Chemical Science (2022).
3. E/Z Photoisomerization of Olefins as an Emergent Strategy for the Control of Stereodivergence in Catalysis. Advanced Synthesis & Catalysis (2022).
4. Photocatalytic Isomerization of (E)-Anethole to (Z)-Anethole. Molecules (2022).