Chlorine Radical Mediated Deprotection of Aryl Ethers via Photocatalyzed Ligand‐to‐Metal Charge Transfer

A new strategy for photocatalytic deprotection of aryl ethers has been developed. In this work, Cl⁻ was converted to the key Cl• via the photocatalyzed LMCT pathway. After the cascade process of hydrogen atom abstraction and oxidation by O₂, ester intermediates were delivered. Furthermore, through simple filtration and subsequent hydrolysis, the deprotection of aryl ethers was ultimately achieved. This synthesis strategy features atom economy, mild conditions, and no need for precious metal catalysts, demonstrating the sustainability.

Abstract

A photochemical FeCl₃-catalyzed the C(sp³ )-H activation of aryl ethers was achieved via hydrogen atom abstraction strategy of chlorine radicals. Followed by the tandem hydrolysis, the aryl ethers were converted into the corresponding phenol products (28 examples). Compared with traditional reductive deprotection methods for aryl ethers, such as Pd/C, Mg/alcohol system and so forth, our strategy features mild reaction conditions, atom economy, and wide functional group compatibility. In addition, several control experiments were conducted to investigate the reasonable mechanism.

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