Part I - A Study of the Formation of Carbenes by Elimination of α-Bromosilanes and Application toward the Synthesis of Transition Metal Complexed Quinone Methide Analogs. Part II - Development of Novel 7-Membered Ring Carbene Ligands for Palladium Catalyzed Cross Coupling Reactions.
Date of Graduation
Doctor of Philosophy in Chemistry (PhD)
Chemistry & Biochemistry
Neil T. Allison
Second Committee Member
Robert E. Gawley
Third Committee Member
Matthias C. McIntosh
Pure sciences, Bromosilanes, Carbenes, Ligands, Palladium catalysis, Quinone methide
In part I, we wish to report our approaches toward transition metal complexed ortho-quinone methide analogs. ortho-Quinone Methides are a class of highly reactive compounds with a wide range of chemical and biological applications. Previously, a stable iron complexed benzannulated 5-membered ring quinone methide analog was reported by Allison and Neal27. Herein, we report our approaches to improve the reactivity of that system by removing benzannulation as well as changing the metal from iron to manganese and rhenium.
Furthermore, a methodological study on generating carbenes under mild conditions by elimination of α-halosilanes and its application towards metal complexed quinone methide analogs will be included.
In part II, we report our attempts toward steric and electronic control of palladium-catalyzed cross coupling reactions by means of 7-membered ring carbene ligands. Cycloheptatrienylidene has recently emerged as an efficient catalyst ligand for both C-C and C-N bond forming reactions.56 Our efforts will focus on fine-tuning both the electronic environment of the metal center by benzannulation of the cycloheptatrienylidene ligand and the steric environment by addition of substituents to the ligand.
Loeschel, C. M. (2012). Part I - A Study of the Formation of Carbenes by Elimination of α-Bromosilanes and Application toward the Synthesis of Transition Metal Complexed Quinone Methide Analogs. Part II - Development of Novel 7-Membered Ring Carbene Ligands for Palladium Catalyzed Cross Coupling Reactions.. Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/437