Concave reagents

Abstract

Concave Reagents are molecules in which standard reagents of organic chemistry are incorporated into concave structures. Via combination of acidic or basic centers with bimacrocyclic systems, Concave Pyridines 1 and 2, Concave 1,10-Phenanthrolines 3 and 4 and Concave Benzoic Acids 5 could be synthesized. The influence of the concave structure on the selectivities of these new reagents could be shown in protonations of nitronate ions and in base-catalyzed additions of alcohols to diphenylketene. Improvements towards enantioselectivity and towards easier recovery (polymer-bound Concave Pyridines) are presented, too. © 1993 IUPAC