乙酸/氧气法高效合成取代卟啉

Acetic Acid/ Oxygen Route for EfficientSynthesis of Substituted Porphyrin

卟啉在结构上可视为是由4个吡咯类亚甲基的α-碳原子通过次甲基桥互联而形成的大分子杂环化合物,具有高度共轭结构。随着卟啉与金属的配合物即金属卟啉的催化特性受到广泛关注,取代卟啉的高效合成日益显示出重要的学术和应用价值。但是现有的丙酸法和乙酸/硝基苯法存在卟啉收率低、环境污染严重等问题,导致取代卟啉的成本居高不下,限制了其广泛应用。本文利用乙酸/氧气法,在120℃下控制反应物浓度为0.24 mol/L,并在反应第一阶段(前30 min)通入氧气,得到四(4-溴苯基)卟啉(化合物d),产率高达53.8%。该方法是高效合成取代卟啉的新方法,卟啉骨架形成和氧化两个反应同时进行,方法简单、绿色且收率高,有望大幅度降低取代卟啉的合成成本。

Recently,efficient synthesis of porphyrin has become increasingly interesting in demand of many discoveries in metalloporphyrin complexes,especially for their excellent catalytic performances.Porphyrin is a conjugated macrocyclic compound composed of four pyrrole rings connected by methenylene.The state-of-the-art porphyrin synthesis includes propionic acid method and acetic acid/nitrobenzene method,but both suffer from low yield,high cost and heavy environmental pollution.In this work,an acetic acid/oxygen route for substituted porphyrin synthesis was developed,where the reaction temperature was kept at 120℃,while O 2 was fed only in the first 30 min under reactant concentration of 0.24 mol/L,leading to tetra(4-bromophenyl)porphyrin in the yield of 53.8%.It should be noted that the acetic acid/oxygen route allows the concurrence of macrocyclic framework formation and oxidation,which provides a viable strategy for efficient porphyrin synthesis in convenient and less environment loading way.