Efforts towards understanding the nickel catalyzed cycloaddition of ciynes and nitriles to make pyridines

Download item | Update item information
Publication Type thesis
School or College College of Science
Department Chemistry
Author Thomas, David Robert
Title Efforts towards understanding the nickel catalyzed cycloaddition of ciynes and nitriles to make pyridines
Date 2014-05
Description Efforts towards understanding the nickel catalyzed cycloaddition of diynes and nitriles to make pyridines are described. During the course of this mechanistic study, a previously uncharacterized class of nickel-nitrile-NHC (N-heterocyclic carbene) dimers, which display cooperative η1 and η2 binding modes of the nitrile to nickel, were discovered. Crystal structures were obtained for select dimers. These dimers proved catalytically competent in the cycloaddition reaction. Pseudo first order kinetics revealed that the reaction was first order in dimer while being zero order in NHC ligand, nitrile, and diyne. While stoichiometric reactions with dimer and diyne in the absence of nitrile did give product, largely improved yields were observed in the presence of free nitrile. Stoichiometric competition studies utilizing various identities of free nitriles and dimers indicated a preference for incorporation of free nitrile into the product versus the dimer-bound nitrile. The results of this study suggest a mechanism involving partial dimer opening as the rate-determining step. This is then followed by nitrile binding, which precedes oxidative coupling with diyne.
Type Text
Publisher University of Utah
Subject Cycloaddition; Pyridine
Dissertation Institution University of Utah
Dissertation Name Master of Science
Language eng
Rights Management Copyright © David Robert Thomas 2014
Format Medium application/pdf
Format Extent 2,726,559 Bytes
Identifier etd3/id/2883
ARK ark:/87278/s6283gs4
Setname ir_etd
Date Created 2014-05-27
Date Modified 2018-04-03
ID 196452
Reference URL https://collections.lib.utah.edu/ark:/87278/s6283gs4