Ligand‐Enabled γ‐C(sp <sup>3</sup> )−H Olefination of Free Carboxylic Acids
Kiron Kumar Ghosh, Alexander Uttry, Arup Mondal, Francesca Ghiringhelli, Philipp Wedi, Manuel van Gemmeren
Abstract
We report the ligand-enabled C-H activation/olefination of free carboxylic acids in the γ-position. Through an intramolecular Michael addition, δ-lactones are obtained as products. Two distinct ligand classes are identified that enable the challenging palladium-catalyzed activation of free carboxylic acids in the γ-position. The developed protocol features a wide range of acid substrates and olefin reaction partners and is shown to be applicable on a preparatively useful scale. Insights into the underlying reaction mechanism obtained through kinetic studies are reported.
Topics & Concepts
Ligand (biochemistry)Carboxylic acidChemistryStereochemistryCombinatorial chemistryMedicinal chemistryOrganic chemistryBiochemistryReceptorCatalytic C–H Functionalization MethodsSynthesis and Catalytic ReactionsAsymmetric Hydrogenation and Catalysis