Pyridylpyrrolides as alternatives to cyclometalated phenylpyridine ligands: synthesis and characterization of luminescent zinc and boron pyridylpyrrolide complexes.

The synthesis, structure, and properties of six luminescent pyridylpyrrolide complexes and the first structural characterization of pyridylpyrrolide metal complexes are reported. A series of new zinc complexes, bis(pyridylpyrrolyl)zinc, (R2PyrPy)2Zn (R = Me, Et, iPr, tBu, and Ph), that vary in their substituents on the pyrrole ring (Me, Et, iPr, tBu, and Ph), were prepared. Pyrrole substitution produced small structural changes in the complexes and affected the fluorescence properties very little.

One-step synthesis of 3,5-disubstituted-2-pyridylpyrroles from the condensation of 1,3-diones and 2-(aminomethyl)pyridine.

3,5-Disubstituted- and 3,4,5-trisubstituted-2-(2-pyridyl)pyrroles may be synthesized efficiently from the novel condensation of 2-(aminomethyl)pyridine and 1,3-diones. The cyclization reaction was found to proceed through the intermediacy of a (2-pyridyl)methylimine. A marked dependence of the regioselectivity in the reaction of unsymmetrical diones on the presence of additional aminomethylpyridine suggests that two pathways to the product pyrroles are available.