PIDA-mediated Oxidative Decarboxylation of Oxamic Acids. The Role of Radical Acidity Enhancement

Chemistry. 2023 Mar 13;29(15):e202202963. doi: 10.1002/chem.202202963. Epub 2023 Feb 24.

Abstract

The PIDA-mediated oxidative decarboxylation of oxamic acids in the presence of alcohols is shown to afford the corresponding urethanes under thermal conditions. Computational and experimental mechanistic exploration allows to rationalize the different reactivity of PIDA as compared to related cyclic BI-OAc and highlights the importance of the enhanced acidity of the proton in the carbamoyl radical intermediate.

Keywords: DFT; acidity; carbamoyl radical; hypervalent iodine; isocyanate; urethane.