Ligand Development Directed Towards Applications in Late Metal Catalysis

Olefin metathesis is a powerful tool in organic chemistry and in the last 20 years has seen prolific expansion. Olefin metathesis has allowed the expedient and concise preparation of otherwise extremely difficult or impossible molecules. The vast majority of research has recently focused on the use of ruthenium olefin metathesis catalysts and relatively simple variations of Grubbs style catalysts.;This research was focused on the preparation and investigation of new ruthenium chemistry and its potential application towards olefin metathesis catalysis. The research hub was the development of new ligand sets and their application. Furthermore, established ligand sets were applied to new applications of ruthenium chemistry and interesting reactivity investigated.;Hitherto, the N-heterocyclic carbenes and phosphines have formed the basis of auxiliary ligands for ruthenium catalysts which most significantly promote catalytic olefin metathesis. The first strategy employed herein was the development of a new class of monodentate ligands. A new class of monodentate heterocyclic phosphinimines is prepared, characterized, and applied. Subsequently, the successful coordination to silver and gold is described. An interesting reaction is also noted with palladium.;In the development of heterocyclic phosphinimines, phosphino-imines were prepared and applied to ruthenium chemistry. Coordination analogues of second generation Grubbs catalyst were prepared. Additionally, investigation into the coordination chemistry to general ruthenium starting materials was investigated and a unique template reaction was observed. The reaction involved the scission of a P-N bond and subsequent formation of a new P,N bidentate ligand.;The final main focus of research was the application of tridentate ligands towards catalytic olefin metathesis. First, bis(imino)pyridine ligands were applied to Grubbs style catalysts and unique reactivity was observed. Second, tridentate phosphinimine ruthenium complexes were prepared and screened for activity in catalytic olefin metathesis.