The Design, Synthesis and Geometric Analysis of Large Centrally Functionalised Porphyrin-Spacer-Porphyrins

Abstract

This thesis describes the design, synthesis and geometric analysis of centrally functionalised Porphyrin-Spacer-Porphyrins (PSPs) that have potential as 'molecular switches' and/or 'artificial enzymes'. The synthetic approach adopted made use of specifically designed functionalised building blocks that could be 'glued' together using a number of well established protocols based on various stereospecific [2+2] and [4+2] cycloaddition reactions. Chapter 2 describes the screening of potential binane and polynorbornane spacer groups using simple computationally generated molecular mechanics models. Details of the subsequent development of general synthetic methods toward fused-oxabridged norbomenes that were judged to have suitable geometric and functional characteristics follow. A general method for the synthesis of variously substituted aryl imides allowed for an efficient introduction of central functionalities into the spacer building blocks. The extension of these systems based on tandem [2+2] cycloaddition reactions (Mitsudo reaction) followed by epoxidation (Sharpless) gave the dual functionalised spacer building blocks.