Concerted Displacement Reactions: The Reaction of Catechol with Acyl Halides^1a,b

Abstract

The rates of reaction of catechol with several acyl halides were determined in 95% acetone. The results indicate that the reaction proceeds by a concerted attack of the monocatecholate ion on the acyl halide with the formation of the monoacyl ester of catechol. Benzenesulfonyl fluoride and benzoic anhydride appear to react with catechol by a similar concerted mechanism. Resorcinol, hydroquinone and phenol are, relative to catechol, unreactive toward acyl halides.

Mechanisms of Catalysis of Nucleophilic Reactions of Carboxylic Acid Derivatives.

“…It is of interest, however, to consider possible bifunctional reactions as a guide to future catalytic possibilities. The rates of reaction of catechol with several acyl halides in 95 per cent acetone indicate a first-order dependence on the monocatecholate ion (112). Furthermore resorcinol, hydroquinone, and phenol are relatively unreactive toward acyl halides.…”

Catechol as a nucleophilic catalyst of peptide bond formation

“…Much more mechanistic information, however, is available for the reactivity of catechol. Its monoanion has been reported to be a much better nucleophile than the phenoxide ion towards a number of carboxylic acid derivatives [5][6][7][8] and towards phosphonofluoridates such as the nerve gases sarin and soman [9][10][11]. On the other hand, catechol monoesters of protected amino acids are known to aminolyse abnormally rapidly without racemization [12,13].…”