Institute of Organic Chemistry of the Polish Academy of Sciences, Kasprzaka 44/52, Warsaw, Poland.
Chem Asian J. 2010 Jan 4;5(1):130-40. doi: 10.1002/asia.200900345.
Four dyads comprised of corrole and coumarin units have been synthesised. Three coumarincarboxaldehydes were synthesized and transformed into the corresponding trans-A(2)B-corroles by reaction with 5-(pentafluorophenyl)dipyrromethane. It has been proven that this type of direct condensation can lead to the corresponding corroles in moderate yields. The reaction of hydroxybenzaldehydes with vinylphosphonium salts has been identified as the most general method for the preparation of formyl-coumarins with various patterns of substituents. The dyad consisting of ketobiscoumarin and corrole was synthesized by Sonogashira coupling. Spectroscopic and photophysical investigations revealed that there is an efficient energy transfer from the coumarin moiety to corrole in all four dyads. Energy transfer can be clearly ascribed to a dipole-dipole mechanism (Förster) for all dyads that contain luminescent coumarins and to an electron exchange mechanism (Dexter) for the dyad with the non-luminescent one. In the case of the dyad that bears coumarin with a hydroxy group at position 5, an electron-transfer was detected from corrole to coumarin. The latter process is possible because of the suitably low reduction potential of coumarins of this type.
已经合成了四个由卟啉和香豆素单元组成的二聚体。通过与 5-(五氟苯基)二吡咯甲烷反应，合成了三种香豆素醛，并将其转化为相应的反式 A(2)B-卟啉。事实证明，这种直接缩合可以以中等产率得到相应的卟啉。确定了羟基苯甲醛与乙烯基膦盐的反应是制备具有各种取代模式的甲酰香豆素的最通用方法。通过 Sonogashira 偶联合成了由酮双香豆素和卟啉组成的二聚体。光谱和光物理研究表明，在所有四个二聚体中，香豆素部分到卟啉的能量转移是有效的。对于所有含有发光香豆素的二聚体，能量转移可以明确归因于偶极-偶极机制（Förster），而对于具有非发光香豆素的二聚体，则归因于电子交换机制（Dexter）。在带有 5-位羟基的香豆素的二聚体的情况下，从卟啉到香豆素检测到电子转移。后一种过程是可能的，因为这种类型的香豆素的还原电位足够低。
