Synthesis and application of dioxocyclams

Abstract

A new class of highly functionalized, penta-coordinate capped dioxocyclams was developed by the alkylation of two secondary amines on the dioxocyclam ring with an aromatic bis-electrophile. An in depth analysis of the complex stereochemistry of the capped dioxocyclams was performed. A new class of bis-dioxocylams was also developed in which the two dioxocyclam rings were linked by an aromatic bridge. The stereochemistry of the bridged bis-dioxocylams was analyzed, and it was discovered that from achiral materials a total of 6 different stereoisomers could be produced, of which only two were observed. The different stereoisomers showed substantially different shapes along with different orientations of the two linked dioxocyclam rings. A copper(II) complex of a capped dioxocyclam was synthesized and the X-ray crystal structures of two different forms of the copper complex were solved. The crystal structures revealed that the differences were due to changes in conformation of the dioxocyclam ligand which changed the coordination geometry around the copper center. Copper(II) complexes of alkoxy-linked bis-dioxocyclams were used as agents for the hydrolysis of activated phosphate diesters. The different bis-dioxocyclam complexes positioned the two copper centers at different distances and a small correlation between copper-copper distance and rate enhancement of hydrolysis was seen. Several new alkoxy linked bis-dioxocylams were synthesized for use as phosphate diester hydrolysis agents.