Four tandem C-H activations: A sequential C-C and C-O bond making via a Pd-catalyzed cross dehydrogenative coupling (CDC) approach

摘要

An unprecedented aroylation at the ortho C-H bond with respect to a directing group has been accomplished via a Pd(II)-catalyzed cross dehydrogenative coupling approach using alkylbenzene as the synthetic equivalent of an aroyl moiety. The reaction proceeds through sequential C-C and C-O bond making at the expense of four consecutive C-H bond cleavages (three sp ~3 benzylic C-H's and one sp ~2 arene C-H) to selectively install an aroyl functionality at the proximal site of substrates containing various directing groups.