Mechanistic Investigations of Iron Pincer Catalysts for the Hydrogenation and Dehydrogenation of Polar Substrates
Date of Award
Doctor of Philosophy (PhD)
This thesis summarizes findings related to understanding of hydrogenation and dehydrogenation of polar substrates by a pincer-supported iron catalyst, (iPrPNHP)Fe(H)2(CO) (iPrPNHP =N(CH2CH2PiPr2)2), including both mechanisms of key elementary reaction steps as well as insight into catalyst decomposition. Chapter 1 gives a brief overview of catalysts that make use of metal-ligand cooperativity (MLC), particularly Noyori-type catalysts supported by the secondary-amine pincer scaffold iPrPNHP. Chapter 2 discusses the synthesis of a second-generation of iron catalysts based on the iPrPNHP ligand with isonitrile ancillary ligands. Chapter 3 discusses the impacts of “proton shuttles” on the reversible activation of H2 by complexes which take advantage of MLC. Chapter 4 discusses insights into decomposition of iron catalysts based on the iPrPNHP ligand derived from the synthesis and stoichiometric reactivity of previously unobserved catalytic intermediates, supported by DFT calculations. Additionally, Chapter 4 provides some guidance on selecting reaction additives that may be able to prevent catalyst decomposition by reversibly sequestering highly-reactive catalytic intermediates.
Smith, Nicholas, "Mechanistic Investigations of Iron Pincer Catalysts for the Hydrogenation and Dehydrogenation of Polar Substrates" (2021). Yale Graduate School of Arts and Sciences Dissertations. 219.