Synthesis of Donor Ligands and Their Applications in Catalysis
- Author(s): DeHope, Alan
- Advisor(s): Bertrand, Guy
- et al.
The discovery of new transition metal mediated homogeneous catalytic reactions, and the improvement of known reactions is oftentimes attributable to changes made to the ancillary ligands bound to a metal center. In the last decades stable carbenes have been recognized as powerful tools for the creation of organometallic complexes which exhibit dramatic increases in activity and stability over analogous complexes featuring tertiary phosphine ligands. The discovery and development of new classes of carbenes has even given rise to new classes of catalytic reactions.
This work is centered on the development of mono amino carbenes which feature a ferrocene directly bound to the carbene center. Indeed, the first aminoferrocenyl carbene has been synthesized. Since acyclic carbenes oftentimes are less stable than their cyclic counterparts, we have targeted cyclic aminoferrocenylcarbenes.
The second portion of this work deals with the study of the deprotonation of isothiazolium salts and the resulting products, 2-amino-thietes. Reactivity of the thietes with amines and lithium amides is reported.
Our group has been active in reporting new families of carbon-based donor ligands. The last part of this work deals with taking ligands developed in our group, namely cyclic bent allenes and abnormal carbenes, and finding applications for them in homogeneous catalysis. This has necessitated the modification of these donor ligands, both sterically and electronically, in order to find more active catalysts. The first palladium and ruthenium complexes of cyclic bent allenes have been prepared. Grubbs style ruthenium olefin metathesis catalyst bearing abnormal carbenes have been developed and their reactivity is described herein.