Progress in Selective Hydrogenation: Reactivity Trends in PdAu Heterogeneous Catalysts & Developing Chiral Building Blocks for New Homogeneous Catalysts
Date
2017-05
Authors
Contributor
Advisor
Department
Instructor
Depositor
Speaker
Researcher
Consultant
Interviewer
Narrator
Transcriber
Annotator
Journal Title
Journal ISSN
Volume Title
Publisher
University of Hawaii at Manoa
Volume
Number/Issue
Starting Page
Ending Page
Alternative Title
Abstract
Selective hydrogenation is an essential method for converting cheap starting materials into more valuable chemical building blocks. Whether regioselectivity or diastereoselectivity is desired, catalysts are often employed to aid in this transformation. This work explores possibilities for finetuning both homogeneous and heterogeneous catalysts. Previously, bimetallic PdAu catalysts were used to enable the conversion of biologically produced 4-hydroxycoumarin (4HC) to pharmaceutically relevant coumarin and dihydroxycoumarin (DHC), but the subtleties of catalyst preparation and the effect of Pd loading were not known. Part I focuses on identifying reactivity trends resulting from variations in PdAu catalysts. Several PdAu catalysts with varying Pd:Au ratios were prepared by controlled surface reactions (CSR) or incipient wetness impregnation (IWI). Using high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GCMS), we determined the effects of the preparation method and Pd loading on reactivity, selectivity, and resistance to deactivation for the selective hydrogenation of 4HC to DHC. Part II aims to develop chiral building blocks for C1-symmetric, P-stereogenic ligands that will be used in the asymmetric hydrogenation of heavily functionalized substrates. To date, a new diastereoselective method of adding RO-H across a P=P double bond was identified and a new sterically dominating R group was generated. The results were analyzed by nuclear magnetic resonance (NMR) spectroscopy.
Description
Keywords
selective hydrogenation, heterogeneous catalysis, biorenewable chemicals, asymmetric hydrogenation, homogeneous catalysis, P-stereogenic ligands
Citation
Extent
34 pages
Format
Geographic Location
Time Period
Related To
Related To (URI)
Table of Contents
Rights
All UHM Honors Projects are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission from the copyright owner.
Rights Holder
Local Contexts
Collections
Email libraryada-l@lists.hawaii.edu if you need this content in ADA-compliant format.