2026-09-20T20:41:38Zhttps://dspace.mit.edu/server/oai/request

oai:dspace.mit.edu:1721.1/987852026-06-16T18:16:29Zcom_1721.1_7582com_1721.1_7581col_1721.1_131022

Gregory C. Fu. Ziegler, Daniel Todd Massachusetts Institute of Technology. Department of Chemistry. Massachusetts Institute of Technology. Department of Chemistry 2015-09-17T19:11:56Z 2015-09-17T19:11:56Z 2015 2015 http://hdl.handle.net/1721.1/98785 921141063 Thesis: Ph. D. in Organic Chemistry, Massachusetts Institute of Technology, Department of Chemistry, 2015. Vita. Cataloged from PDF version of thesis. Includes bibliographical references. Chapter 1 describes the development of chiral biphenyl-derived phosphepines and their application as catalysts for an asymmetric [4 + 1] annulation to form functionalized cyclopentenes bearing a non-spirocyclic quaternary stereocenter. Additional studies demonstrate the synthetic utility of the cyclopentene products for further stereoselective functionalization and provide insight into the mechanism of the reaction. Chapter 2 describes the development of photoinduced, copper-catalyzed C-N couplings between aromatic nitrogen heterocycles (i.e., indole, benzimidazole, imidazole, and carbazole) and aryl, alkenyl, and alkynyl halides. These reactions utilize an inexpensive catalyst (Cul, without an additional ligand) and proceed at unusually low temperature for Ullmann coupling processes with these heterocycles (room temperature). Additional studies probe the selectivity of the reaction with respect to both the nucleophilic and the electrophilic coupling partner. Chapter 3 details progress towards developing a method for asymmetric, intermolecular y additions of oxygen nucleophiles to alkynoates using a chiral phosphine catalyst. Conditions are presented that effectively couple alkynoates bearing an aryl substituent at the y position with a variety of alcohols in good yield and high ee. Future efforts will be focused on expanding the scope of this process and conducting experiments to gain insight into the reaction mechanism. by Daniel Todd Ziegler. Ph.D. in Organic Chemistry 304 pages eng Massachusetts Institute of Technology M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 Chemistry. Chiral phosphine-catalyzed asymmetric transformations of allenoates and alkynoates and photoinduced, copper-catalyzed C-N couplings with aromatic nitrogen ceterocycles Thesis application/pdf false Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="e6ca9ff0-87cd-4f7a-9170-14b4da5d7879"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>Chiral phosphine-catalyzed asymmetric transformations of allenoates and alkynoates and photoinduced, copper-catalyzed C-N couplings with aromatic nitrogen ceterocycles</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2015</PublicationDate> <Authors> <Author> <DisplayName>Ziegler, Daniel Todd</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Chemistry.</Keyword> <Abstract>Chapter 1 describes the development of chiral biphenyl-derived phosphepines and their application as catalysts for an asymmetric [4 + 1] annulation to form functionalized cyclopentenes bearing a non-spirocyclic quaternary stereocenter. Additional studies demonstrate the synthetic utility of the cyclopentene products for further stereoselective functionalization and provide insight into the mechanism of the reaction. Chapter 2 describes the development of photoinduced, copper-catalyzed C-N couplings between aromatic nitrogen heterocycles (i.e., indole, benzimidazole, imidazole, and carbazole) and aryl, alkenyl, and alkynyl halides. These reactions utilize an inexpensive catalyst (Cul, without an additional ligand) and proceed at unusually low temperature for Ullmann coupling processes with these heterocycles (room temperature). Additional studies probe the selectivity of the reaction with respect to both the nucleophilic and the electrophilic coupling partner. Chapter 3 details progress towards developing a method for asymmetric, intermolecular y additions of oxygen nucleophiles to alkynoates using a chiral phosphine catalyst. Conditions are presented that effectively couple alkynoates bearing an aryl substituent at the y position with a variety of alcohols in good yield and high ee. Future efforts will be focused on expanding the scope of this process and conducting experiments to gain insight into the reaction mechanism.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>