文摘
This work has established the first direct homocoupling of unactivated electron-deficient azaarenes in the presence of TMPMgCl (2,2,6,6-tetramethylpiperidinylmagnesium chloride) and TMEDA (tetramethylethylenediamine). In this process, no transition metal was used while freely available air was employed as the oxidant. The investigated successful substrates included quinolines, isoquinoline, 3-phenylated pyridines, and 2-phenylated quinoxalines, giving moderate to high yields. The homocoupling of quinolines was effectively scaled up to one gram in high yield. Additionally, an iridium complex of 6,6′-dimethyl-2,2′-biquinoline was prepared and characterized as an efficient red-emitting material.