자료유형  

 학위논문

Control Number  

0017164098

International Standard Book Number  

9798342714587

Dewey Decimal Classification Number  

540

Main Entry-Personal Name  

Rynders, Kathryn.

Publication, Distribution, etc. (Imprint  

[S.l.] : University of Minnesota., 2024

Publication, Distribution, etc. (Imprint  

Ann Arbor : ProQuest Dissertations & Theses, 2024

Physical Description  

283 p.

General Note  

Source: Dissertations Abstracts International, Volume: 86-05, Section: B.

General Note  

Advisor: Tonks, Ian A.

Dissertation Note  

Thesis (Ph.D.)--University of Minnesota, 2024.

Summary, Etc.  

요약Multicomponent reactions are in the forefront of synthetic methodology because they allow multiple transformations to occur in a single step. These reactions maintain high atom and step-economy, increasing synthetic efficiency and allowing for a decrease in chemical waste from things such as workups and purification. Herein, efforts to expanding the use of phenonium ions, azatitanacyclobutenes, and Pauson-Khand type reactions to further multicomponent reactions are reported. First, benzylic or homobenzylic stereocenters are present in many biorelevant natural products. These stereocenters are commonly installed via cross-coupling reactions employing expensive and/or inefficient transition metal catalysis. Mechanistic studies on an already established system to form these stereocenters via phenonium ions reveal the reaction to be complete in under 3 minutes and attempts to slow the reaction down to perform kinetic studies resulted in a change of mechanism. Next, the selective manipulation of C−C bonds is a growing area of research. We reported a formal insertion of diazo compounds into the sp2−sp3 C−C bond of benzyl bromide derivatives catalyzed by a simple Lewis acid. This regioselective reaction proceeds via a phenonium ion intermediate. Second, we report a new hydroaminative cyclization for 1,6 and 1,7 enynes using a simple Ti-imido precatalyst, [py2TiCl2(NPh)]2. The well-known [2+2] azatitanacyclobutadiene cycloadduct intermediate is intercepted by tethered alkenes, followed by protonolysis of the resultant metallacycle. Next, previously reported by the Tonks group was the synthesis of pyrazoles by a Ti-mediated multiple-component reaction using alkynes and nitriles. This work herein studies the effects of the intramolecular reaction of alkynes and nitriles under these conditions as well as using alkyne-nitriles under Fe/Ru catalysis conditions to form pyrazoles. Finally, precedented Ti-catalyzed Pauson-Khand reactions use expensive or non-commercially available Ti-catalysts which are not benchtop stable. We proposed that inexpensive commercially available TiCl4(THF)2 could be capable of catalyzing a Pauson-Khand reaction, based on previous reports on benchtop Ti-catalyzed pyrrole synthesis.

Subject Added Entry-Topical Term  

Chemistry.

Subject Added Entry-Topical Term  

Organic chemistry.

Subject Added Entry-Topical Term  

Inorganic chemistry.

Index Term-Uncontrolled  

Azatitanacyclobutenes

Index Term-Uncontrolled  

Lewis acid

Index Term-Uncontrolled  

Pauson-Khand reactions

Added Entry-Corporate Name  

University of Minnesota Chemistry

Host Item Entry  

Dissertations Abstracts International. 86-05B.

Electronic Location and Access  

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Control Number  

joongbu:656323