Intramolecular Hydroamination Reactions Catalyzed by Neutral and Cationic Group-IV Pyridylamido Complexes

ZrIV and HfIV benzyl (neutral or cationic) and amido catalysts stabilized by pyridylamido ligands are found to be good candidates for the intramolecular hydroamination/cyclization of primary and secondary aminoalkenes. In particular, cationic monobenzyl derivatives have shown remarkable catalytic activity for the production of five and six-membered N-containing heterocycles from secondary amino alkenes. In addition, ZrIV and HfIV amido derivatives that are produced by a temperature-controlled prototropic rearrangement have provided evidence of the central role played by the metal coordination sphere in promoting such catalytic transformations efficiently.