The use of preformed sodium carboxylates as substrates led to the first observation of facile Pd-insertions into sp(3) beta-C-H bonds in simple aliphatic acids. Consequently, Pd-catalyzed methylation and arylation of o-C-H bonds in benzoic acids and beta-C-H bonds in aliphatic acids using either a phenylboronate, methylboronic acid, or ArI have been achieved via a C-H activation/C-C coupling sequence.