Gallium tri-chloride derivatives of the sterically demanding pyridines 2,6-Ar2C6H3N (Ar = 2,4,6-Me3C6H2 or 2,4,6-Pri3C6H2)

The sterically demanding pyridines 2,6-Ar2C6H3N [Ar = 2,4,6-Me3C6H2 (1) or 2,4,6-Pri3C6H2 (2)] were prepared by a palladium catalysed Kumada C–C coupling reaction in high yield. Pyridine 1 reacted with one equivalent of GaCl3 to afford the tetra-chloro gallate–pyridinium ion pair complex [GaCl4]−[2,6-(2,4,6-Me3C6H2)2C6H3NH]+ (3). Contrastingly, pyridine 2 reacted with one equivalent of GaCl3 to afford the anticipated donor-acceptor complex [GaCl3{2,6-(2,4,6-Pri3C6H2)2C6H3N}] (4). Complexes 1–4 have been characterised variously by single crystal X-ray diffraction, NMR, CHN, and mass spectrometry.

Two sterically demanding pyridines were prepared by palladium catalysed Kumada coupling and their coordination towards gallium tri-chloride was investigated.Figure optionsDownload as PowerPoint slide