[4-(Ph3b)-2,6-mes(2)py](-): A Sterically Demanding Anionic Pyridine

The introduction of a triphenylborate group at the 4-position of 2,6-dimesitylpyridine afforded a sterically demanding anionic pyridine. The charge introduced through the borate group drastically increases its basicity and measurement of its pK(a) value (18.46) revealed a significantly higher value than that of 4-dimethylaminopyridine (17.95). THF ring-opening was observed upon treating its lithium salt with TMSCl, which demonstrates its high nucleophilicity. The mesityl groups at the 2,6-positions are oriented orthogonal to the pyridine ring and do not block the nitrogen atom of the pyridine. The reaction of the protonated pyridine with Li[BH4] yielded the corresponding Lewis acid/base adduct, which shows that the title compound can be used as a monodentate ligand in coordination chemistry. The crystal structures of all the compounds presented in this work are reported.