Photoinduced Low‐Valent Zirconium Catalysis for Cross‐Electrophile Coupling of Ethers

Abstract

AbstractAccessing versatile C(sp3)−C(sp3) bond through the cross‐electrophile coupling of two distinct etheric C−O bonds is crucial in organic synthesis but remains barely explored. Herein, we report an innovative photoinduced low‐valent zirconocene catalysis enabling the reductive coupling of ethers with high activity and cross‐selectivity. Mechanistic investigation suggests that photoexcitation of low‐valent zirconocene facilitates the C(sp3)−O bond scission of benzylic ethers, leading to the benzylic radicals intermediate via a single‐electron reduction pathway. The subsequent recombination of this benzylic radical with the Zr center followed by carbomagnesiation generates benzylic Grignard reagents for downstream coupling with aliphatic ethers through an SN2‐like mechanism. In application, a wide range of ethers readily in situ derived from aldehydes and ketones becomes feasible with high functional group compatibility as well as excellent cross‐selectivity.