Ligand-Accelerated ortho-C-H Alkylation of Arylcarboxylic Acids using Alkyl Boron Reagents

A protocol for the Pd(II)-catalyzed ortho-C-H alkylation of phenylacetic and benzoic acids using alkylboron reagents is disclosed. Monoprotected amino acid ligands (MPAA) were found to significantly promote reactivity. Both potassium alkyltrifluoroborates and alkylboronic acids were compatible coupling partners. The possibility of a radical alkyl transfer to Pd(II) was also investigated.