Finally, we sought to explore the reasons why 2-aminopyridine was a particularly challenging substrate for catalytic amidation reactions using boron catalysts (Table ). Direct amidation of benzylamine/benzoic acid proceeds efficiently with 10 mol% 2-chorophenyl boronic acid catalyst, giving a 79% yield of amide. Addition of increasing quantities of 2-aminopyridine to this reaction leads to significant lowering of the yield demonstrating that 2-aminopyridine is not simply a poor substrate for the reaction, it actively inhibits the process. 4-aminopyridine or 4dimethylaminopyridine (4-DMAP) also inhibit the reaction but to a significantly lesser extent.