Herein we disclose an iron-catalyzed method to access skeletal rearrangement reactions akin to the Dowd–Beckwith ring expansion from unactivated C­(sp3)–H bonds. Photoinduced ligand-to-metal charge transfer at the iron center generates a chlorine radical, which abstracts electron-rich C­(sp3)–H bonds. The resulting unstable alkyl radicals can undergo rearrangement in the presence of suitable functionality. Addition to an electron deficient olefin, recombination with a photoreduced iron complex, and subsequent protodemetalation allow for redox-neutral alkylation of the resulting radical. Simple adjustments to the reaction conditions enable the selective synthesis of the directly alkylated or the rearranged-alkylated products. As a radical clock, these rearrangements also enable the measurement of rate constants of addition into various electron deficient olefins in the Giese reaction.

To achieve efficient utilization of solar power for environmental remediation, search for suitable materials as efficient solar light driven photocatalysts is one of the most challenging missions. In this work, F-doped (NH 4 ) 0.33 WO 3 was first synthesized as a novel near-infrared (NIR) photocatalyst with enhanced photocatalytic activity. Compared to that of pure ammonium tungsten bronze, a blue shift of the NIR plasmon band and an enhanced NIR absorbance of F-doped (NH 4 ) 0.33 WO 3 could be observed. 83% of rhodamine B (RhB) was degraded by F-doped (NH 4 ) 0.33 WO 3 under NIR irradiation within 180 min. The NIR photodegradation rate of the optimal F-doped (NH 4 ) 0.33 WO 3 for RhB was 0.0102 min −1 , about 8.5 times as high as that of (NH 4 ) 0.33 WO 3 . The enhanced NIR photocatalytic performance of F-doped (NH 4 ) 0.33 WO 3 can be attributed to the remarkable enhanced generation and separation of NIR localized surface plasmon resonance induced electron−hole pairs. Moreover, the F-doped (NH 4 ) 0.33 WO 3 nanorods could also degrade 36% of RhB and 93% of RhB when exposed to the UV light and visible light, respectively. This work develops a promising photocatalyst with a full solar light response for future cleanup of environmental pollutants.

We report the FeCl3-catalyzed alkylation of nonactivated C(sp3)–H bonds. Photoinduced ligand-to-metal charge transfer at the iron center generates chlorine radicals that then preferentially abstract hydrogen atoms from electron-rich C(sp3)–H bonds distal to electron-withdrawing functional groups. The resultant alkyl radicals are trapped by electron-deficient olefins, and the catalytic cycle is closed by Fe(II) recombination and protodemetalation.

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