2015 Theses Doctoral

Part I: Catalytic Carbonyl-Olefin Metathesis. Part II: Cyclopropenimines as Achiral Superbases.

Griffith, Allison Kathleen

This thesis details the development and exploration of a catalytic carbonyl-olefin metathesis reaction. A catalytic transformation of this type has not been accomplished previously and stoichiometric processes were neither general nor desirable. A simple hydrazine catalyst was found to effect this reaction with the use of strained olefins. The development and optimization of this reaction, including the hydrazine catalyst, conditions and substrates, is discussed. Computational studies of the reaction mechanism are included. A stepwise process in which less strained olefins can undergo the reaction is also explored. Lastly, some initial explorations of transition metal complexes as catalysts for a carbonyl-olefin metathesis reaction are discussed, as well.
In the second portion of this thesis, the use of cyclopropenimines as achiral organic superbases will be detailed. Previously, the Lambert group has developed this class of compounds as viable catalysts for asymmetric Michael and Mannich reactions. Cyclopropenimines are more basic than other commonly used organic bases, and therefore, can activate less acidic substrates. A simple, achiral cyclopropenimine was developed for use in base catalyzed or mediated processes. Several reactions have been explored as a comparison of cyclopropenimines to other commonly used bases.