Rapid Access to Supramolecular C–H Oxidation Catalysts via Convergent Synthesis

Controlling the oxidation of unactivated C(sp³)–H bonds through supramolecular catalyst–substrate interactions has recently enabled site-selective transformations previously considered inaccessible. However, progress has been hampered by lengthy linear syntheses of supramolecular catalysts. Here we present a concise, convergent two-step strategy that directly cross-couples pre-formed tetradentate aminopyridine ligands with recognition motifs, streamlining access to functional catalysts. Using this approach, we prepared two catalysts, both featuring resorcin[4]arene units for substrate recognition using the solvophobic effect in 2,2,2-trifluoroethanol. These catalysts oxidize alkyl substrates selectively at the fifth C–H bond, a preference absent in unsubstituted analogues. This convergent synthesis not only overcomes the limitations of previous four- to five-step linear routes but also provides a broadly applicable platform for rapid construction of catalyst libraries, enabling systematic exploration of recognition-driven C–H oxidation.