A Regel-type transition-metal-free direct C-2 aroylation of (benzo)oxazoles, (benzo)thiazoles and 1,3,4-oxadiazoles with acid chlorides catalyzed by N,N-dimethyl-4-aminopyridine (DMAP) is described. This methodology is effective with several aroyl and heteroaroyl chlorides affording the corresponding 2-ketoazoles in moderate to excellent yields.
DONDONI, ALESSANDRO;FANTIN, GIANCARLO;FOGAGNOLO, MARCO;MEDICI, ALESSANDRO+, J. ORG. CHEM., 53,(1988) N 8, 1748-1761