Carboxylate as a Non-innocent L-Ligand: Computational and Experimental Search for Metal-Bound Carboxylate Radicals

Org Lett. 2022 Jun 3;24(21):3817-3822. doi: 10.1021/acs.orglett.2c01356. Epub 2022 May 24.

Abstract

We show that the carboxylate radical acts as an L-ligand with certain high-spin transition metal centers. Such coordination preserves the O-radical character needed for C-H activation via hydrogen atom transfer. Capture of the new C-radical by the metal and subsequent reductive elimination leads to formal C-H acyloxylation. Decarboxylation of the RCO2 radical is minimized through hybridization effects introduced by spiro-cyclopropyl moiety.