A combinedexperimental and computationalstudy on the key intermediates of NHC-catalyzed acylation reaction, Breslow intermediates (BIs), has been conducted in order to achieve a direct nucleophilic alkanoylation of N-heterocycles. Various BI precursors are alternatively prepared and used in the reaction with 4-chloroquinazoline. The present study reveals that the intermediates having benzimidazole