Alexandria Digital Research Library

Homogeneous Gold Catalysis : Ligand Design and Reactions of Alkynes

Author:
Wang, Yanzhao
Degree Grantor:
University of California, Santa Barbara. Chemistry
Degree Supervisor:
Liming Zhang
Place of Publication:
[Santa Barbara, Calif.]
Publisher:
University of California, Santa Barbara
Creation Date:
2014
Issued Date:
2014
Topics:
Chemistry, Organic
Keywords:
Catalysis
Ligand
Homogeneous
Gold
Alkyne
Heterocycle
Genres:
Online resources and Dissertations, Academic
Dissertation:
Ph.D.--University of California, Santa Barbara, 2014
Description:

In the past dozen years, great progress has been made in developing highly efficient homogenous gold catalysis. As soft "pi" Lewis acids, cationic gold(I) complexes are particularly powerful in terms of activating alkyne/allene towards nucleophilic attack, leading to a variety of synthetically versatile structures. During my research, several synthetic methods have been developed, including: (1) Au-catalyzed ligand-directed anti nucleophilic attack of alkynes; the new ligands I developed enable highly efficient gold-catalyzed nucleophilic addition of acids, anilines and water to the alkynes; and catalyst loadings could be lowered to 10 parts per million; (2) rapid access of chroman-3-ones via gold-catalyzed oxidation of propargyl aryl ethers; this step-economic and efficient transformation was realized by a bulky gold catalyst, Me4tBuXPhosAuNTf2 and bulky electron-deficient pyridine N-oxides derived from Hantzsch esters; (3) Au-catalyzed novel indole synthesis via a key [3,3] sigmatropic rearrangement; 2-alkylindoles were produced with high regioselectivity and efficiency from easily accessed N-arylhydroxylamines under mild conditions; an improved approach involved cooperative dual catalysis of Zn and Au was developed; much broader substrate scope, shorter reaction time and good to excellent yields were achieved.

Physical Description:
1 online resource (285 pages)
Format:
Text
Collection(s):
UCSB electronic theses and dissertations
ARK:
ark:/48907/f35x2726
ISBN:
9781321203318
Catalog System Number:
990045116520203776
Rights:
Inc.icon only.dark In Copyright
Copyright Holder:
Yanzhao Wang
File Description
Access: Public access
Wang_ucsb_0035D_12146.pdf pdf (Portable Document Format)