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DOE OSTI · 1865407

Photoresponsive Azobenzene-Functionalized Shell Cross-Linked Micelles for Selective Asymmetric Transfer Hydrogenation

Liu, Fangbei·Qu, Peiyuan·Weck, Marcus
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Abstract

We describe the substrate-selective asymmetric transfer hydrogenation of aromatic ketones using rhodium complexes immobilized on a photoresponsive nanoreactor. The nanoreactor is based on multifunctional amphiphilic poly(2-oxazoline)s that are covalently cross-linked with functionalized azobenzene after micelle formation in water. The nanoreactor switches its morphology upon light irradiation in a wavelength-selective manner as confirmed by dynamic light scattering. Kinetic studies show that the gated behavior induced by the phototriggered reversible isomerization of trans- azobenzene to cis- azobenzene in the cross-linking layer is key to discriminate among substrates and reagents during catalysis. Under UV light irradiation, the diffusion of larger substrates into the core is slower in comparison to smaller substrates. The nanoreactor displays substrate selectivity, converting smaller ketone-substrates faster to the corresponding secondary alcohols.

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Liu, Fangbei, Qu, Peiyuan, Weck, Marcus. 2022-04-27. Photoresponsive Azobenzene-Functionalized Shell Cross-Linked Micelles for Selective Asymmetric Transfer Hydrogenation. https://doi.org/10.1021/acs.orglett.2c00925

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