Reactivity of hydrazines with low-valent late metal complexes: Implications for the oxidative addition of nitrogen-nitrogen bonds and the development of a catalytic hydrohydrazination reaction

This work focuses on the fundamental reactivity of hydrazines with low-valent late transition metal systems directed toward the development of amination reactions of olefins with hydrazines. Catalytic hydroamination and diamination of unsaturated hydrocarbons provide efficient routes to a variety of amines. The redox neutral addition of an amine N-H bond to an olefin gives a substituted amine. Diaminations of olefins, however, are oxidative processes and generally require sacrificial oxidants. A direct analogy to the hydroamination reaction would be the direct addition of an N-N bond across a C-C multiple bond. This process can be envisoned to occur by oxidative addition of a hydrazine to a metal center to make an oxidizing amido complex, with subsequent addition of the amido ligands to the alkene. The fundamental reactivity of hydrazines with low-valent late transition metal systems, however, is not developed.;This thesis describes the reactivity of hydrazines and related compounds with low valent Ru, Ir, Rh, Pt, and Ni complexes. The first chapter discusses the formation of a RuIII bis(anilide) dimer, [Cp*RuCl(mu-NHPh)] 2 formed from oxidative addition of 1,2-diphenylhydrazine. This dimer shows limited reactivity with olefins, highlighting the propensity of the anilide ligands to bridge. The following chapter explores the reaction chemistry of hydrazines, tetrazenes, and alkoxyamines with various electron rich late metal systems. In no case is reaction with the N-N or N-O bond observed. Instead, reactivity is often observed with the much stronger N-H bond, suggestive of a kinetic barrier to N-N and N-O oxidative additions. The final chapter presents the development and mechanistic study of a new Pt-catalyzed intramolecular hydrohydrazination reaction to form N-amino lactams. Based on stoichiometric and catalytic reactions of isolated Pt-alkyl and Pt-amidate complexes, we propose a mechanism involving C-N bond formation by alkene insertion into a Pt-N bond. Reflected in each chapter are the challenges associated with the use of hydrazines for diamination reactions.