Probing the reactivity of uncommon palladium oxidation states

Bouley, Bailey Samuel

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https://hdl.handle.net/2142/124662 Copy

Description

Title

Probing the reactivity of uncommon palladium oxidation states

Author(s)

Bouley, Bailey Samuel

Issue Date

2024-04-17

Director of Research (if dissertation) or Advisor (if thesis)

Mirrica, Liviu M

Doctoral Committee Chair(s)

Mirrica, Liviu M

Committee Member(s)

• Girolami, Gregory S
• Vura-Weis, Joshua
• Fataftah, Majed

Department of Study

Chemistry

Discipline

Chemistry

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Palladium
• Nickel: Cross-Coupling
• Organometallic
• Mechanism

Abstract

The chemistry of palladium (Pd) has been extensively interrogated in the last few decades, especially in the realm of bond forming reactions. Carbon-carbon (C-C) cross-coupling reactions are one of the most prevalent modern pharmaceutical transformations, and are commonly mediated by homogeneous Pd-based catalysts. Traditionally, most Pd cross coupling perform under a unified catalytic cycle, operating in even oxidation states (0/II) with remarkable predictability and stability. However, as we expand our repertoire of reactivity, the so-called “odd” oxidation states have garnered additional academic scrutiny, especially in photochemical and radical-based processes. Accessing this chemistry with intention has potential benefits, as (I/III) cycles could result in lower rates of β-hydride elimination due to poorer d-orbital overlap with alkyl ligands, allowing the use of sp3 reactants, and radical oxidative addition processes could allow for the use of electrophiles that cannot be easily activated with classical Pd catalysts. Despite these potential benefits, the unstable nature of Pd(I) and Pd(III) complexes makes characterization of these ions difficult, and our understanding of how odd oxidation state Pd complexes react is limited. Our group has shown that pyridinophane macrocycles can be used to stabilize these oxidation states to probe their reactivity by creating a distorted octahedral geometry around the metal ion. This strategy has been expanded upon in this document to explore not only the high, but also the low-valent chemistry in the areas of Pd(I/III) catalytic transformations and C-H activation. These results help to better frame the general reactivity principles of these uncommon palladium oxidation states.

Graduation Semester

2024-05

Type of Resource

Thesis

Copyright and License Information

Copyright 2024 Bailey Bouley

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