Mitasev, Branko
(2007)
Transition Metal-Catalyzed Reactions of Allenes in Diversity-Oriented Synthesis.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Transition metal-catalyzed cyclization reactions involving allenes were demonstrated as useful methods for the synthesis of novel heterocyclic compounds. Multiple scaffolds were accessed from pivotal allenic amino-ester intermediates by varying the reaction conditions. Rhodium(I)-catalyzed allenic Alder-ene reaction of allenynes afforded cross-conjugated trienes in high yields. Double bond selectivity in the allenic cyclocarbonylation reaction of allenynes was accomplished by utilizing either rhodium(I)-catalyzed or molybdenum-mediated conditions, thus gaining access to 4-alkylidene or α-alkylidene cyclopentenones, respectively. In addition, a detailed study of the molybdenum-mediated reaction uncovered an unexpected diastereocontrol element based on the amino acid side chain. Furthermore, replacement of the alkyne with an alkene led to discovery of a novel rhodium(I)-catalyzed cycloisomerization of ene-allenes affording tetrahydroazepines. The novel molecular scaffolds obtained in this manner were studied in complexity generating reactions that were employed in the synthesis of libraries of compounds for biological evaluation. For example, stereoselective sequential Diels-Alder reactions of the cross-conjugated trienes allowed rapid access to polycyclic molecular skeletons. Additionally, a Stetter/Paal-Knorr reaction sequence was developed to gain access to novel tricyclic pyrroles.
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Details
| Item Type: |
University of Pittsburgh ETD
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| Status: |
Unpublished |
| Creators/Authors: |
|
| ETD Committee: |
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| Date: |
22 June 2007 |
| Date Type: |
Completion |
| Defense Date: |
20 December 2006 |
| Approval Date: |
22 June 2007 |
| Submission Date: |
6 February 2007 |
| Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
| 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: |
biological screening; combinatorial synthesis; cycloisomerization; drug discovery |
| Other ID: |
http://etd.library.pitt.edu/ETD/available/etd-02062007-082443/, etd-02062007-082443 |
| Date Deposited: |
10 Nov 2011 19:31 |
| Last Modified: |
15 Nov 2016 13:36 |
| URI: |
http://d-scholarship.pitt.edu/id/eprint/6336 |
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