Facile and Efficient Synthesis of Functionalized Asymmetric Porphyrins with Organolithium Reagents

Mathias Senge,Xiangdong Feng

doi:10.3390/ecsoc-4-01903

Abstract

Functionalized asymmetric porphyrins bearing highly reactive centers in substituents at the mesopositions were synthesized in good yields by the reaction of 5,15-diphenylporphyrin with organolithium reagents. Using these porphyrins as precursors highly complex tetrapyrrolic systems are accessible. The synthetic strategy is based on our earlier reports on the combined use of organolithium and alkyliodide reagents for the functionalization of porphyrins.

Highlights

Tetrapyrroles have broad technical applications in the area of catalysis [2], nonlinear optics [3], receptors for molecular recognition [4], photosensitizers [5], and medicinal applications (PDT)
The porphyrin skeleton is very resilient towards many reactions that should proceed quite on paper like Friedel-Crafts or Grignard reactions and so far, only a few efficient functionalization reactions have been described for porphyrins [6,7]., Especially, the direct, regioselective introduction of functional groups was rather limited up to now
We found that porphyrins readily undergo meso substitution reactions with organolithium reagents [10] and since have developed this reaction to a generally applicable method for the for the preparative synthesis of the functionalized asymmetric porphyrin precursors

Summary

Introduction

Tetrapyrroles have broad technical applications in the area of catalysis [2], nonlinear optics [3], receptors for molecular recognition [4], photosensitizers [5], and medicinal applications (PDT). Further development of these applications requires asymmetric and highly functionalized compounds. Novel and efficient synthetic methods, preferentially via a simple modification of accessible symmetric porphyrins have to be developed.

Results

Conclusion