Graduation Year

2019

Document Type

Dissertation

Degree

Ph.D.

Degree Name

Doctor of Philosophy (Ph.D.)

Degree Granting Department

Chemistry

Major Professor

Xiaodong Michael Shi, Ph.D.

Committee Member

Jianfeng Cai, Ph.D.

Committee Member

Shengqian Ma, Ph.D.

Committee Member

Chuanhai Cao, Ph.D.

Committee Member

Ruisheng Liu, Ph.D.

Keywords

Gold catalysis, Cyclopentenes, Alkene Functionalization

Abstract

This dissertation mainly contains two parts: one is C-X (C, O, S) bond formation through gold(I) catalysis, one is new applications via gold(I/III) redox catalysis.

In first part, gold(I) catalysts would be introduced and their general applications, then the TA-Au species will be emphasized including the design, synthesis, characters and their application in catalysis. The applications are well developed during the past decade in our group, but here only involves three examples regarding C-C, C-O and C-S bond formations. From these effective applications, the unique stability and reactivity of TA-Au will be studied and explained, which is the reason and value of TA-Au discovery.

In second part, gold(I/III) redox catalysis will be presented through two application examples: cross-coupling of terminal alkynes, multiple bond di-functionalization. The most challenging part for coupling reactions is the competition between homo-coupling and cross-coupling products, while in our project, we have successfully developed a new method to selectively obtain cross-coupling as major product to homo-coupling product (ratio 12:1). Later on, we found a new method to achieve gold (I/III) redox cycle by using mild oxidant diazonium salt instead of PIDA or Selectfluor strong oxidant. The new mild and efficient method have largely extended the application of gold(I/III) redox catalysis into organic synthesis.

In sum, the new gold catalysts and catalysis methods reported here are important to the development of gold catalysis field, which are critical and useful to help people understand the reason of applying noble gold species as catalysts, and the advantages that other metals do not have.

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