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Updated: Jul 9, 2025

Light-driven Enzymatic Decarboxylation
Published on: May 22, 2016
Metal-Free 1,3-Boronate Rearrangement to Ketones Driven by Visible Light
Kejia Hao1, Defang Li1,2, Dongmin Fu3
1State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai, 200032, China.
Abstract:
Boronate rearrangements, such as the Matteson and Petasis reactions, are valuable metal-free reactions for the transfer of the carbo group on boron to intramolecular electrophilic sites. However, only highly reactive electrophiles are suitable, and ketones are too inactive for those boronate rearrangements due to the high energy barriers. We disclose here the 1,3-boronate rearrangement to ketones, for which a high energy barrier (44.9 kcal/mol) is prohibitory for thermal reactions in the ground state. The reaction is enabled by the key keto-enol-boronate bidentate complex formation in situ, which absorbs visible light to reach the excited state for the chemoselective 1,3-boronate rearrangement to ketones. Experimental and computational investigations exclude free radical intermediates from organoboronates. The aryl, alkenyl, and alkyl boronic acids react with various 1,3-diketones driven by visible light irradiation to construct structurally diverse β-keto tertiary alcohols under metal-free conditions. The reaction demonstrates substrate diversity with 58 examples, yields up to 98 %, and it is suitable for gram-scale synthesis.
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