Construction of functionalized nitrogen heterocycles using 2-(diphenylphosphoryl)oxygen-1,3-butadienes in multicomponent [4+2] cycloaddition reactions
department or school: Science, Faculty of
department or school: Chemistry, Department of
data provider: DSpace
degree campus: UBCV
creator: He, Qiuyu
issued: 2023-08-15T19:50:34Z
issued: 2023
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: This dissertation presents research work on hetero-Diels-Alder reactions using 2-diphenylphosphoryloxy-1,3-butadienes and imines for the construction of six-membered nitrogen heterocycles. Chapter 1 provides an overview of hetero-Diels-Alder reactions that primarily focuses on imines and enol-based dienes. Chapter 2 describes hetero-Diels-Alder reactions between 2-diphenylphosphoryloxy-1,3-butadienes and imines under the promotion of iron(III) chloride. Twelve examples of 2-diphenylphosphoryloxy-1,3-butadienes were synthesized, and eighteen cycloaddition products were constructed in 30–91% isolated yields. Relative configurations of products formed in diastereomeric mixtures were analyzed by 2-dimensional NMR spectroscopy, and the diastereomeric ratios ranged from 2:1 to >20:1. The utility of the enol phosphate functionality was demonstrated in manipulations of the cycloaddition products in transition metal catalyzed cross-coupling reactions. Chapter 3 describes the multicomponent hetero-Diels-Alder reactions using dienes from Chapter 2, amines, and aldehydes through in situ generation of iminium species under the promotion of boron trifluoride diethyl etherate. The reactions were carried in non-distilled dichloromethane without the use of inert atmosphere. Thirty-one examples of cycloaddition products were presented with a diverse scope of aromatic aldehydes, aliphatic aldehydes, N-sulfonyl amines, and N-carbamoyl amines. Chapter 4 describes a sequence of cycloaddition–cross-coupling–oxidation reactions to construct functionalized pyridines. The N-Fmoc substituted cycloaddition products were subjected to Pd(0)-catalyzed Kumada coupling reactions with varied Grignard coupling partners. The Fmoc protecting group in the cross-coupling products was deprotected using piperidine. A subsequent addition of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone oxidized the heterocyclic ring to an aromatic pyridine structure. Twenty examples of disubstituted pyridines and one example of…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/85474
note: CONSTRUCTION OF FUNCTIONALIZED NITROGEN HETEROCYCLES USING 2-(DIPHENYLPHOSPHORYL)OXYGEN-1,3-BUTADIENES IN MULTICOMPONENT [4+2] CYCLOADDITION REACTIONS by Qiuyu He B. Sc. (Hons.), The University of Toronto, 2019 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Chemistry) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) August 2023 © Qiuyu He, 2023 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the dissertation entitled: Construction of Functionalized Nitrogen Heterocycles Using 2-(Diphenylphosphoryl)oxygen-1,3-Butadienes in Multicomponent [4+2] Cycloaddition Reactions submitted by Qiuyu He in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Chemistry Examining Committee: Gregory Dake, Associate Professor, Chemistry, UBC Supervisor Jason Hein, Associate Professor, Chemistry, UBC Supervisory Committee Member Michael Wolf, Professor & Head, Chemistry, UBC University Examiner Abby Collier, Professor, Pharmaceutical Sciences, UBC University Examiner Additional Supervisory Committee Members: Glenn Sammis, Professor, Chemistry, UBC Supervisory Committee Member Eva Nichols, Assistant Professor, Chemistry, UBC Supervisory Committee Member iii Abstract This dissertation presents research work on hetero-Diels-Alder reactions using 2-diphenylphosphoryloxy-1,3-butadienes and imines for the construction of six-membered nitrogen heterocycles. Chapter 1 provides an overview of hetero-Diels-Alder reactions that primarily focuses on imines and enol-based dienes. Chapter 2 describes hetero-Diels-Alder reactions between 2-diphenylphosphoryloxy-1,3-butadienes and imines under the promotion of iron(III) chloride. Twelve examples of 2-diphenylphosphoryloxy-1,3-butadienes were synthesized, and eighteen cycloaddition products were constructed in 30–91% isolated yields…
has type: Thesis/Dissertation
date issued: 2023-11
is shown at: 10.14288/1.0435211
language: eng
degree discipline: Chemistry
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Dake, Gregory
type: Text
identifier URI: http://hdl.handle.net/2429/85474