Li, Xiben
(2014)
Endeavors in Methodology Development and Natural Product Total Synthesis.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
This thesis deals with the development of new reaction methodology, as well as total synthesis of natural products.
Chapter 1 describes readily available rhodium(II) salts catalyzed B-H insertion reactions between NHC-boranes (NHC-BH3) and diazocarbonyl compounds (N2CR1COR2). Stable α-NHC-boryl carbonyl compounds (NHC-BH2-CHR1COR2) are isolated in good yields. The reaction is a reliable way to make boron-carbon bonds with good tolerance for variation in both the NHC-borane and diazocarbonyl components. It presumably occurs by insertion of a transient rhodium carbene into a boron-hydrogen bond of the NHC-borane. Competition experiments show that a typical NHC-borane is highly reactive toward rhodium carbenes.
Chapter 2 describes the synthetic routes towards the synthesis of tulearin A and tulearin C. Large scale synthesis of the bottom fragments (C1-C12) and the top fragment (C13-C26) for tulearin A was accomplished. Different synthetic routes were tested to accomplish the total synthesis of tulearin A. Some major problems toward the total synthesis of tulearin A were identified and solved. Meanwhile a novel synthetic route towards the total synthesis of tulearin C was developed. New methodologies were applied to make the synthesis more efficient. The total synthesis of tulearin C was not accomplished because of the difficulty of removal of the acetate protecting group at C17.
Share
| Citation/Export: |
|
| Social Networking: |
|
Details
| Item Type: |
University of Pittsburgh ETD
|
| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
|
| Date: |
29 May 2014 |
| Date Type: |
Publication |
| Defense Date: |
7 March 2014 |
| Approval Date: |
29 May 2014 |
| Submission Date: |
24 March 2014 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| Number of Pages: |
182 |
| Institution: |
University of Pittsburgh |
| Schools and Programs: |
Dietrich School of Arts and Sciences > Chemistry |
| Degree: |
PhD - Doctor of Philosophy |
| Thesis Type: |
Doctoral Dissertation |
| Refereed: |
Yes |
| Uncontrolled Keywords: |
Boron-Hydrogen bond insertion, NHC-Boranes, Total synthesis, Tulearins |
| Date Deposited: |
29 May 2014 17:13 |
| Last Modified: |
15 Nov 2016 14:18 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/20815 |
Metrics
Monthly Views for the past 3 years
Plum Analytics
Actions (login required)
 |
View Item |
![[feed]](/images/feed-icon-32x32.png){kind=icon}