Reductive Animation - A Convenient Method for Generating Diverse, Mono-Functionalised 5,10,15,20-Tetraphenyl Porphyrins

摘要

Formylation followed by reductive amination of 5,10,15,20-tetraphenyl porphyrin (TPP) is shown to be a versatile synthetic procedure for monosubstitution of the porphyrin core re-giospecifically at one P-position. A diverse range of substituents can be introduced in this way in good yields, including cyclen aza-crown macrocycles.Porphyrins are aromatic tetrapyrrolic macrocycles, which are found widely in nature where they play vital roles in photosynthesis, cellular respiration, oxygen transport and storage, and as components of metalloenzymes.1 The functions performed by porphyrins in nature have driven research into the use of synthetic porphyrins in many areas including artificial photosynthetic systems,2 as oxidation catalysts3 and in photodynamic therapy of cancer.4 In order to integrate porphyrins into biomimetic systems and fine-tune their optical and redox properties for these applications, efficient methods for functionalising the porphyrin core are constantly under investigation.