Aluminum Chloride Activation of Chloro-Boronsubphthalocyanine: a Rapid and Flexible Method for Axial Functionalization with an Expanded Set of Nucleophiles

作者：Morse Graham E; Bender Timothy P^*

来源：Inorganic Chemistry, 2012, 51(12): 6460-6467.

DOI：10.1021/ic2016935

We have developed a process whereby chloroboronsubphthalocyanine (Cl-BsubPc) and other BsubPcs are activated to reaction with oxygen, sulfur, and nitrogen based nucleophiles by treatment with aluminum chloride under mild conditions. This allows for the scope of atoms chemically bound to the boron atom to be expanded beyond those derived from the traditional oxygen and carbon based nucleophiles. The successful formation of thiophenoxy and phenylamino derivatives of BsubPc was confirmed spectroscopically and by X-ray crystallography of single crystals. We have proposed a detailed mechanism for this process based on experimental observation and NMR spectroscopy (H-1, B-11, and Al-27) which involves formation of a complex between a halo-BsubPc and AlCl3 (which we denote BsubPc(Cl)center dot Al(Cl')(3)). Our observations indicate that the action of phenol on BsubPc(Cl)center dot Al(Cl')(3) does not involve direct reaction at the boron atom; rather phenol first reacts at the aluminum atom along the way to the formation of a new intermediate complex BsubPc(OPh)center dot Al(O'Ph)(3). The consequence is that the rate of this process is independent of the nature of the starting BsubPc. Cl-BsubPc and Br-BsubPc as well as BsubPcs with peripheral substitutents all react to form their respective phenoxy derivatives at the same rate. Quenching of BsubPc(OPh)center dot Al(O'Ph)(3) with a Lewis base ultimately produces a new bond between the phenol nucleophile and the boron atom of the BsubPc.

• 出版日期2012-6-18