Login

Publications  •  Project Statistics

Glossary  •  Schools  •  Disciplines
People Search: 
   
Title/Abstract Search: 

Dissertation Information for Bing Liu

NAME:
- Bing Liu

DEGREE:
- Ph.D.

DISCIPLINE:
- Chemistry

SCHOOL:
- Emory University (USA) (2000)

ADVISORS:
- Albert Padwa

COMMITTEE MEMBERS:
- Frank E. McDonald
- Debra L. Mohler

MPACT Status: Fully Complete

Title: Application of cycloaddition and cyclization chemistry for alkaloid synthesis

Abstract: "The intermolecular Diels-Alder reaction of 2-amidofurans provides a versatile approach toward the synthesis of a variety of hydroindole ring systems. Employing this cycloaddition chemistry as the key step, the synthesis of the Amaryllidaceae alkaloids hippadine and (¡À)-crinane as well as the Dendrobium alkaloid (¡À)-dendrobine was accomplished from readily available starting materials. This strategy should be of general utility for the synthesis of more complex hydroindole alkaloids.

Cyclic 2-amidofurans can be synthesized using an intramolecular Diels-Alder reaction of 2-amino-substituted oxazoles that contain a tethered alkyne. This transformation represents a new route to this rare heterocyclic ring system. This protocol was successfully used for a formal synthesis of the pyrrolophenanthridone alkaloids hippadine and ungeremine.

The intramolecular dipolar cycloaddition of thioisom¨¹nchnones generated from N-monosubstituted thioamides and ¦Á-bromoalkenoyl chlorides represents a highly effective method for the synthesis of the core indolo[2,3- a ]quinolizidine skeleton found in yohimbine. In the case of thioamides which contain an ¦Á-hydrogen, deprotonation to form the S,N -ketene acetal proceeds much faster than formation of thioisom¨¹nchnones. A short synthesis of (¡À)-alloyohimbane using this bicycloannulation of carboline-1-thione was demonstrated to highlight the synthetic utility of thioisom¨¹nchnones in organic synthesis.

Cyclization of diazo lactams with Rh(II) catalysts was studied. The decomposition of these diazo keto-lactams with Rh(II) catalysts provides a concise approach to both indolizinone and quinolizinone skeletons through an initially formed transient epoxide. Rearrangement of the transient epoxide is highly dependent upon the substitution about the epoxide ring."

MPACT Scores for Bing Liu

A = 0
C = 0
A+C = 0
T = 0
G = 0
W = 0
TD = 0
TA = 0
calculated 2008-04-10 16:13:57

Advisors and Advisees Graph