Quaternary Charge-Transfer Complex Enables Photoenzymatic In-termolecular Hydroalkylation of Olefins

02 November 2020, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Intermolecular C–C bond-forming reactions are underdeveloped transformations in the field of biocatalysis. Here we report a photoenzymatic intermolecular hydroalkylation of olefins catalyzed by flavin-dependent ‘ene’reductases. Radical initiation occurs via photoexcitation of a rare high-order enzyme-templated charge-transfer complex that forms between an alkene, 𝛼-chloroamide, and flavin hydroquinone. This unique mechanism ensures that radical formation only occurs when both substrates are present within the protein active site. This active site can control the radical terminating hydrogen atom transfer, enabling the synthesis of enantioenriched γ-stereogenic amides. This work highlights the potential for photoenzymatic catalysis to enable new biocatalytic transformations via previously unknown electron transfer mechanisms.


Charge-Transfer Complex
Asymmetric Catalysis

Supplementary materials

Supplemental Information


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