Synthesis of Bulky N ‐Acyl Heterocycles by DMAPO/Boc 2 O‐Mediated One‐Pot Direct N ‐Acylation of Less Nucleophilic N ‐Heterocycles with α‐Fully Substituted Carboxylic Acids

This report describes a general method for the one‐pot direct N ‐acylation of N ‐heterocycles using our previously developed 4‐( N , N ‐dimethylamino)pyridine N ‐oxide (DMAPO)/di‐ tert ‐butyl dicarbonate (Boc 2 O) system. This system enables one‐pot N ‐acylation reactions to provide bulky N ‐acyl heterocycles starting from a wide variety of less nucleophilic N ‐heterocycles and sterically hindered α‐fully substituted carboxylic acids in high yields. Moreover, this one‐pot method does not involve pre‐activation of substrates. The protocol has been successfully extended to one‐pot N ‐acylation of 7‐azaindoles.