摘要：Xuefeng Jiang − Shanghai Key Laboratoryof Green Chemistry and Chemical Processes, State Key Laboratory of PetroleumMolecular & Pro

转自：康龙化成

Deprotection of Benzyl-DerivedGroups via Uranyl-Photocatalysis

Jiaolong Meng, Lei Ji, and Xuefeng Jiang*

Xuefeng Jiang − Shanghai Key Laboratoryof Green Chemistry and Chemical Processes, State Key Laboratory of PetroleumMolecular & Process Engineering, School of Chemistry and MolecularEngineering, Hainan Institute of East China Normal University, Shanghai 200062,China; School of Chemistry and Chemical Engineering, Henan Normal University,Xinxiang, Henan 453007, China; State Key Laboratory of OrganometallicChemistry, Shanghai Institute of Organic Chemistry, Chinese Academy ofSciences, Shanghai 200032, China;

Jiaolong Meng & Lei Ji −Shanghai Key Laboratory of Green Chemistry and Chemical Processes, State KeyLaboratory of Petroleum Molecular & Process Engineering, School ofChemistry and Molecular Engineering, Hainan Institute of East China NormalUniversity, Shanghai 200062, China

—Organometallics, 2024,43, 1682−1686

Recommended by Yilong Zhao_MC2

KEYWORDS: Debenzylation (反应类型),photocatalysis (反应类型),H-O(成键类型), benzylsubstrates (原料), UO2(OAc)2·2H2O (催化剂), Phenol (产物)

ABSTRACT: Tocircumvent the hazards associated with flammable/explosive hydrogen and addresssubstrate compatibility issues in reductive systems, we developed a mild methodfor benzyl deprotection facilitated by uranium under visible light irradiationat ambient conditions. The uranium-oxo species, as a metal-oxo-typephotosensitizer, demonstrates compatibility with moisture, enabling benzyl C.Hactivation through ligand-to-metal charge transfer (LMCT) excitation.Subsequent capture of the benzyl radical by atmospheric oxygen inducesoxidation at the benzylic position. Removal of the semiacetal occurs, resulting in C.O bond cleavage under acidic conditions. Thismethodology, featuring mild conditions and operational convenience, iscompatible with moisture and oxygen. It presents a complementary strategy forbenzyl deprotection forthe synthesis of pharmaceuticals and organic materials.

Background and this work

Reaction screening

Substrate scppe

Proposedmechanism

Prof.Xuefeng Jiang and co-workers have developed a mild strategy for the oxidativedeprotection of benzyl-derived groups by cleavage of the C−O bonds under bluelight. The uranyl cation enables benzyl C−H activation through ligand-to-metalcharge transfer (LMCT) excitation. Subsequent capture of the benzyl radical by O2 induces oxidation at the benzylicposition, resulting in C−O bond cleavage under acidic conditions. Thismethodology has demonstrated a broad substrate scopebearing ester, ketone, CN, NO2,X etc. group and is moisture- andoxygen-compatible,suitablefor late-stage debenzylation in pharmaceutical synthesis. Additionally, thisstrategy features straightforward operation and can be easily scaled up togram-scale preparation, which demonstrates its potential for industrialapplication.

来源：新浪财经一点号