Imination reactions of free and coordinated 2-diphenylphosphino-1-phenyl-phospholane: Access to regioisomeric ruthenium(ii) complexes containing novel iminophosphorane–phosphine ligands

Abstract

In this work, selective monoimination reactions of free and Ru-coordinated 2-diphenylphosphino-1-phenyl-phospholane with diphenylphosphoryl azide or 4-azido-2,3,5,6-tetrafluorobenzonitrile are described. Following this approach, a large variety of neutral and cationic mono- and dinuclear (η⁶-arene)–ruthenium(II) complexes containing regioisomeric iminophosphorane–phosphine ligands could be prepared and, in some cases, structurally characterized by means of X-ray diffraction methods. The catalytic activity of these ruthenium complexes, both in racemic or enantiomerically pure form, in Diels–Alder cycloaddition reactions is also presented.