Nonspectator Reactivity of Nontrigonal Tricoordinate Phosphorus Ligands

This thesis describes novel ‘nonspectator’ reactivity of geometrically deformed tricoordinate phosphorus ligands that diverge from traditional supporting roles of phosphines in transition metal catalysis. Chapter 1 presents an overview of the chemistry of higher coordinate phosphorus ligands in tran...

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Main Author: Tanushi, Akira
Other Authors: Radosevich, Alexander Thomas
Format: Thesis
Published: Massachusetts Institute of Technology 2022
Online Access:https://hdl.handle.net/1721.1/144087
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author Tanushi, Akira
author2 Radosevich, Alexander Thomas
author_facet Radosevich, Alexander Thomas
Tanushi, Akira
author_sort Tanushi, Akira
collection MIT
description This thesis describes novel ‘nonspectator’ reactivity of geometrically deformed tricoordinate phosphorus ligands that diverge from traditional supporting roles of phosphines in transition metal catalysis. Chapter 1 presents an overview of the chemistry of higher coordinate phosphorus ligands in transition metal complexes. Chapter 2 describes experiments validating the enhanced electrophilicity of nontrigonal Cₛ-symmetric P(III) compounds as compared to typical trigonal P(III) ligands with quasi-C₃ᵥ local symmetry. Specifically, phosphorus K-edge XANES spectroscopy combined with time-dependent DFT calculation reveal ca. 1.5 eV bathochromic shift in the position of P K-edge onset. In Chapter 3, the development of nonspectator reactivities of a novel chelating ligand containing a nontrigonal P(III) center with Group 8 Ru complexes is presented. In a first finding, a unique net insertion of nontrigonal P(III) ligand into a Ru–H bond, yielding a five-coordinate phosphorus center in which of the substituents is a transition metal (i.e. metallohydrophosphoranes). The mechanistic investigation of the net insertion shows an α-H-migration between Ru–P bond in a reversible and controllable fashion. Chapter 4 extends the nonspectator reactivity to metal–ligand cooperative bond activation to Group 9 metal systems. Various transformations, such as heterolytic splitting of carbon dioxide and cooperative O–H addition of phenol, are achieved by a designed Ir–P bond with a bifunctional reactivity. Finally, Chapter 5 presents results on the net insertion of nontrigonal P(III) ligands into Group 10 metal–carbon bonds, and the factors governing the insertion reactivity is discussed. Taken together, the versatile nonspectator reactivities provide a conceptually new role of higher coordinate phosphorus ligands as a viable platform for novel bond activation and group transfer processes.
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spelling mit-1721.1/1440872022-07-28T03:36:23Z Nonspectator Reactivity of Nontrigonal Tricoordinate Phosphorus Ligands Tanushi, Akira Radosevich, Alexander Thomas Massachusetts Institute of Technology. Department of Chemistry This thesis describes novel ‘nonspectator’ reactivity of geometrically deformed tricoordinate phosphorus ligands that diverge from traditional supporting roles of phosphines in transition metal catalysis. Chapter 1 presents an overview of the chemistry of higher coordinate phosphorus ligands in transition metal complexes. Chapter 2 describes experiments validating the enhanced electrophilicity of nontrigonal Cₛ-symmetric P(III) compounds as compared to typical trigonal P(III) ligands with quasi-C₃ᵥ local symmetry. Specifically, phosphorus K-edge XANES spectroscopy combined with time-dependent DFT calculation reveal ca. 1.5 eV bathochromic shift in the position of P K-edge onset. In Chapter 3, the development of nonspectator reactivities of a novel chelating ligand containing a nontrigonal P(III) center with Group 8 Ru complexes is presented. In a first finding, a unique net insertion of nontrigonal P(III) ligand into a Ru–H bond, yielding a five-coordinate phosphorus center in which of the substituents is a transition metal (i.e. metallohydrophosphoranes). The mechanistic investigation of the net insertion shows an α-H-migration between Ru–P bond in a reversible and controllable fashion. Chapter 4 extends the nonspectator reactivity to metal–ligand cooperative bond activation to Group 9 metal systems. Various transformations, such as heterolytic splitting of carbon dioxide and cooperative O–H addition of phenol, are achieved by a designed Ir–P bond with a bifunctional reactivity. Finally, Chapter 5 presents results on the net insertion of nontrigonal P(III) ligands into Group 10 metal–carbon bonds, and the factors governing the insertion reactivity is discussed. Taken together, the versatile nonspectator reactivities provide a conceptually new role of higher coordinate phosphorus ligands as a viable platform for novel bond activation and group transfer processes. Ph.D. 2022-07-27T18:21:24Z 2022-07-27T18:21:24Z 2021-09 2022-07-27T11:43:36.609Z Thesis https://hdl.handle.net/1721.1/144087 0000-0002-9461-5529 In Copyright - Educational Use Permitted Copyright MIT http://rightsstatements.org/page/InC-EDU/1.0/ application/pdf Massachusetts Institute of Technology
spellingShingle Tanushi, Akira
Nonspectator Reactivity of Nontrigonal Tricoordinate Phosphorus Ligands
title Nonspectator Reactivity of Nontrigonal Tricoordinate Phosphorus Ligands
title_full Nonspectator Reactivity of Nontrigonal Tricoordinate Phosphorus Ligands
title_fullStr Nonspectator Reactivity of Nontrigonal Tricoordinate Phosphorus Ligands
title_full_unstemmed Nonspectator Reactivity of Nontrigonal Tricoordinate Phosphorus Ligands
title_short Nonspectator Reactivity of Nontrigonal Tricoordinate Phosphorus Ligands
title_sort nonspectator reactivity of nontrigonal tricoordinate phosphorus ligands
url https://hdl.handle.net/1721.1/144087
work_keys_str_mv AT tanushiakira nonspectatorreactivityofnontrigonaltricoordinatephosphorusligands