Sarkar, Nihar Ranjan
(2010)
ALKENYL IMINIUM ION IN DIELS-ALDER REACTION: SYNTHESIS OF HIGHLY SUBSTITUTED N-HETEROCYCLES.
Doctoral Dissertation, University of Pittsburgh.
(Unpublished)
Abstract
Heterocyclic structures are critical components of an extensive collection of chemotherapeutic agents, either in service or under development, for treating numerous human illnesses. As a result, reaction technologies for heterocycle construction, in the context of both target- and diversity-oriented synthesis, enjoy a particularly prominent role in medicinal chemistry. Amongst all the C-C bond forming reactions, the classic Diels-Alder cycloaddition remains one of the most powerful transformations in organic chemistry especially for the formation of heterocyclic structures. Herein, we report a new methodology based on inverse electron demand Diels-Alder reaction utilizing reactive "N-alkenyl iminium ion" and a suitable dienophile for the stereoselective synthesis of substituted piperidine derivatives. In presence of a suitable Lewis acid, the "N-alkenyl iminium ion" is generated from the respective enamine-aminal derivative in situ and undergoes Diels-Alder reaction with a dienophile producing a highly substituted N-heterocycle (piperidine derivative) in one step.An efficient transition metal catalyzed isomerization technique for the synthesis of a new enamine-aminal synthon from respective N-allylamine derivatives has been developed. Cationic Ir-(COE) complex, a potential catalyst for ICR chemistry, was used for the isomerization of tosyl protected N-allylamine derivatives to synthesize N-tosyl-alkenyl iminium ion precursor in high geometrical selectivity and quantitative yield whereas carbamate (or amide) protected N-allylamine derivatives were isomerized with good E/Z ratio using Grubbs II.
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Details
Item Type: |
University of Pittsburgh ETD
|
Status: |
Unpublished |
Creators/Authors: |
Creators | Email | Pitt Username | ORCID  |
---|
Sarkar, Nihar Ranjan | nrs17@pitt.edu | NRS17 | |
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ETD Committee: |
Title | Member | Email Address | Pitt Username | ORCID |
---|
Committee Chair | Nelson, Scott G | | | | Committee Member | Doemling, Alexander | | | | Committee Member | Wilcox, Craig | | | | Committee Member | Floreancig, Paul | | | |
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Date: |
28 January 2010 |
Date Type: |
Completion |
Defense Date: |
7 December 2009 |
Approval Date: |
28 January 2010 |
Submission Date: |
15 November 2009 |
Access Restriction: |
5 year -- Restrict access to University of Pittsburgh for a period of 5 years. |
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: |
N-HETEROCYCLES; ORGANIC SYNTHESIS; IMINIUM ION; PIPERIDINE |
Other ID: |
http://etd.library.pitt.edu/ETD/available/etd-11152009-132705/, etd-11152009-132705 |
Date Deposited: |
10 Nov 2011 20:04 |
Last Modified: |
15 Nov 2016 13:51 |
URI: |
http://d-scholarship.pitt.edu/id/eprint/9680 |
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