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Tropylium-Catalyzed O-H Insertion Reactions of Diazoalkanes with Carboxylic Acids

Claire Empel, Thanh Vinh Nguyen* and Rene M. Koenigs*

*University of New South Wales, Sydney 2052, NSW, Australia; RWTH Aachen University, D-52074 Aachen, Germany, Email:,

C. Empel, T. V. Nguyen, R. M. Koenigs, Org. Lett., 2021, 23, 548-553.

DOI: 10.1021/acs.orglett.0c04069

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Nonbenzenoid aromatic carbocation can be used as organic Lewis acid catalysts in O-H functionalization reactions of diazoalkanes with benzoic acids. The reported protocol with tropylium is applicable to a wide range of diazoalkanes and carboxylic acids with excellent efficiency.

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proposed mechanism

Key Words

α-hydroxy esters, alkylative esterification

ID: J54-Y2021