Molecular Recognition in the Selective Oxygenation of Saturated C-H Bonds by a Dimanganese Catalyst

Although enzymes often incorporate molecular recognition elements to orient substrates selectively, such strategies are rarely achieved by synthetic catalysts. We combined molecular recognition through hydrogen bonding with C-H activation to obtain high-turnover catalytic regioselective functionalization of sp3 C-H bonds remote from the -COOH recognition group. The catalyst contains a Mn(mu-O)2Mn reactive center and a ligand based on Kemp's triacid that directs a -COOH group to anchor the carboxylic acid group of the substrate and thus modify the usual selectivity for oxidation. Control experiments supported the role of hydrogen bonding in orienting the substrate to achieve high selectivity.