3 - Multiple pathways in cyclodextrin-catalyzed hydrolysis of perfluoro-alkylamides

ALEJANDRO M. GRANADOS; RITA H. DE ROSSI

AMER CHEMICAL SOC

Lugar: Washington; Año: 1995 vol. 117 p. 3690 - 3690

he hydrolysis of p-nitroanilide of perfluoroalkanoic acids, CF3(CF2),,CO-, with n = 1, 2, 3, 5, 6, and 7, la-f, was studied in the presence of P-cyclodextrin (CD). All reactions were catalyzed by CD through the formation of a 1:l and 1:2 inclusion complexes. The association equilibrium constants for the 1:l complexes were dependent on the number of carbons of the fluoroalkyl chain, whereas those of the 1:2 complexes were almost independent. These results indicate that, in the former case, the perfluoroalkyl chain is included, while in the latter, the CD unit encloses the aryl ring. For compounds la,b both complexes were more reactive than the substrate itself. The ratio of the reaction of complexed to uncomplexed substrate had its highest value for la in the case of the 1:l complex, and for lb, the 1:2 complex. This is attributed to the geometry of the complexes. Although compounds lc-e reacted at the same rates in the free or 1: 1 complexed form, CD accelerated the reactions