PASSIVE TEMPLATE EFFECTS AND ACTIVE ACID-BASE INVOLVEMENT IN CATALYSIS OF ORGANIC-REACTIONS

A series of receptors were prepared all containing two adenine binding sites linked by various spacers. Their ability to act as templates in the coupling of two adenine derivatives, an active ester and an amine , in CHCl3 was evaluated. The accelerations varied from none to 700-fo ld. Binding studies of the coupling product with these templates confi rmed involvement of both binding sites. When the spacer was a 1,10-phe nanthroline unit, an efficient hydrolysis reaction of the active ester was observed. Another series of receptors were prepared containing on e adenine receptor and various polar functional groups. The molecules were evaluated as catalysts in the coupling of an adenine-derived acti ve eater and n-butylamine. The orientation as well as the nature of th e functional group greatly influenced the coupling rate. A carboxylate group was most effective, accelerating the intracomplex reaction 250- fold.