Direct, Site‐Selective and Redox‐Neutral α‐C−H Bond Functionalization of Tetrahydrofurans via Quantum Dots Photocatalysis

Abstract

As one of the most ubiquitous bulk reagents available, the intrinsic chemical inertness of tetrahydrofuran (THF) makes direct and site-selective C(sp 3 )−H bond activation difficult, especially under redox neutral condition. Here, we demonstrate that semiconductor quantum dots (QDs) can activate α-C–H bond of THF via forming QDs/THF conjugates. Under visible light irradiation, the resultant alkoxyalkyl radical directly engages in radical cross-coupling with α-amino radical from amino C–H bonds or radical addition with alkene or phenylacetylene, respectively. In contrast to stoichiometric oxidant or hydrogen atom transfer reagents required in previous studies, the scalable benchtop approach can execute α-C–H bond functionalization of THF only by a QD photocatalyst under redox-neutral condition, thus providing a broad of value added chemicals starting from bulk THFs reagent. The high step- and atom-economy, high efficiency and broad substrate scope make the photocatalysis with QDs and visible light promising in both academic and industrial setting.