(Amidomethyl)pyridine zirconium and hafnium complexes: Synthesis and structural characterization

A series of 2-formyl and 2-acetylpyridines was condensed with 2,6-diisopropylaniline to yield the corresponding imines. Their reaction with sodium borohydride gave the respective N-arylaminomethylpyridines. Treatment of the N-arylformimino- or -acetiminopyridines with trimethylaluminum followed by hydrolysis furnished a series of the respective substituted N-arylaminoethylpyridine derivatives. Their reaction with tetrabenzylzirconium or tetrakis(dimethylamido)zirconium or -hafnium gave the corresponding (chelate ligand)MX3 systems in a variety of cases. Some of these gave very active ethene polymerization catalysts upon activation with methylalumoxane. Six of the neutral aminoalkylpyridines were characterized by X-ray diffraction, as were eight of the zirconium or hafnium complexes and two aluminum chelate complex systems.

Graphical abstractA series of substituted N-arylaminoalkylpyridine derivatives were synthesized and used as ligands for (chelate ligand)MX3 systems (M = Zr,Hf).2-Formyl and 2-acetylpyridines were condensed with 2,6-diisopropylaniline to yield the corresponding imines. Their reaction with sodium borohydride gave the respective N-aryl aminomethylpyridines. Treatment of the N-arylformimino- or -acetiminopyridines with trimethylaluminum followed by hydrolysis furnished a series of the respective chelate ligands. Their reaction with tetrabenzylzirconium or tetrakis(dimethylamido)zirconium or -hafnium gave the corresponding complex systems in a variety of cases. Some of these gave very active ethene polymerization catalysts upon activation with methylalumoxane. Six of the neutral aminoalkylpyridines were characterized by X-ray diffraction, as were eight of the zirconium or hafnium complexes and two aluminum chelate complex systems.Figure optionsDownload full-size imageDownload as PowerPoint slide