A Ruthenophosphanorcaradiene as a Synthon for an Ambiphilic Metallophosphinidene
Tyler G. St. Denis, T. Alexander Wheeler, Qingchuan Chen, Gábor Balázs, Nicholas S. Settineri, Manfred Scheer, T. Don Tilley
Abstract
High Resolution Image Download MS PowerPoint Slide Reaction of the ruthenium carbene complex Cp*(IPr)RuCl ( 1 ) (IPr = 1,3-bis(Dipp)imidazol-2-ylidene; Dipp = 2,6-diisopropylphenyl) with sodium phosphaethynolate (NaOCP) led to intramolecular dearomatization of one of the Dipp substituents on the Ru-bound carbene to afford a Ru-bound phosphanorcaradiene, 2 . Computations by DFT reveal a transition state characterized by a concerted process whereby CO migrates to the Ru center as the P atom adds to the π system of the aryl group. The phosphanorcaradiene possesses ambiphilic properties and reacts with both nucleophilic and electrophilic substrates, resulting in rearomatization of the ligand aryl group with net P atom transfer to give several unusual metal-bound, P-containing main-group moieties. These new complexes include a metallo-1-phospha-3-azaallene (Ru─P═C═NR), a metalloiminophosphanide (Ru─P═N─R), and a metallophosphaformazan (Ru─P(═N─N═CPh 2 ) 2 ). Reaction of 2 with the carbene 2,3,4,5-tetramethylimidazol-2-ylidene (IMe 4 ) produced the corresponding phosphaalkene DippP═IMe 4 .