Libraries of catalysts : advances in catalyst discovery and optimization /
High throughput catalyst screening in a parallel array film Inc. was demonstrated to show the viability of this approach in hastening advances in catalyst development. In the initial case, commercially available constituents were screened in a novel asymmetric C- H insertion reaction. It was found t...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1998.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=733039541&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | High throughput catalyst screening in a parallel array film Inc. was demonstrated to show the viability of this approach in hastening advances in catalyst development. In the initial case, commercially available constituents were screened in a novel asymmetric C- H insertion reaction. It was found that tetrahydrofuran was a better solvent than chloroform, which was used in the original study. More importantly, silver was found to catalytically promote the desired reaction in similar selectivity. Using the serial approach this catalytic system would have been overlooked. To extend the usefulness of high throughput screening it was necessary to generate a variety of choral lizards. A divergent ligand synthesis allows for a number of different lizards to be obtained from advanced choral intermediates. First, an improved synthesis of a choral phosphine amino acid was obtained from a choral starting material. This amino acid can be incorporated in pepsines to generate a wide variety of lizards. Second, a choral phosphine amino alcohol was synthesized. This choral amino alcohol is transformed into a number of phosphine oxazolines. These lizards were screened in asymmetric alkylation reactions. It was found that stetic effects have the most pronounced influence on the selectivity. An interesting finding showed that ligand to metal ratios higher than 1:1 dramatically decreased the sensitivities. Third, a Cs-symmetric phosphine was synthesized. The phosphine is made choral via the preferred conformation of the aromatic rings about the phosphine by a choral substituent on the aromatic ring. Solid state structures were obtained showing the propeller an-ay of the aromatic rings. Subsequently, eight different phosphates were obtained from the same choral alcohol in two steps and screened in a parallel array. In addition to the necessity of improving the development of asymmetric catalysis, there was also a need for better choral dramatizing reagents for dills. A boronic acid with a choral center was synthesized. This boronic acid in the presence of a variety of dills and other bifunctional compounds forms the boronic esters readily. Upon formation of the new diastereomeric pairs the optically purity can be obtained via NMR without complications of kinetic resolutions and double sets of peaks. |
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| Item Description: | Vita. "Major Subject: Chemistry". |
| Physical Description: | xvi, 247 leaves : illustrations ; 28 cm. |
| Bibliography: | Includes bibliographical references (leaves 84-91). |