AN EFFECTIVE METHOD FOR ACYLATION OF WEAKLY NUCLEOPHILIC ANILINES WITH SILYL CARBOXYLATES VIA MIXED ANHYDRIDES

In the presence of a catalytic amount of active titanium(IV) salt gene rated in situ from 1 mol of TiCl4 and 2 mol of AgOTf, weakly nucleophi lic anilines react under mild conditions with nearly equimolar amounts of silyl carboxylates to afford the corresponding anilides in excelle nt yields using 4-(trifluoromethyl)benzoic anhydride. The mixed anhydr ide formed in situ from trimethylsily acetate and 4-(trifluoxomethyl)b enzoic anhydride, a key intermediate of this reaction, was detected by H-1 NMR experiment. Further, it was shown that the reaction of the mi xed anhydrides and 2-nitroaniline was faster than that of the correspo nding home anhydrides and 2-nitroaniline.