The University of Southampton
University of Southampton Institutional Repository

Studies on O-alkylisoureas in solution phase and on solid support

Studies on O-alkylisoureas in solution phase and on solid support
Studies on O-alkylisoureas in solution phase and on solid support

The use of polymer-supported reagents is proving to be an ideal methodology for the clean and efficient preparation of chemical libraries.  Polymer-supported reagents for the oxidation of alcohols and for the O-alkylation of carboxylic acids were studied.  Several polymer-supported sulfoxides were prepared in order to accomplish catch-and-release oxidations of primary and secondary alcohols.  Unfortunately, an efficient protocol for the oxidations with purification of the intermediate polymer-supported sulfoxonium ion could not be achieved.

A protocol for the synthesis of polymer-supported O-alkylisoureas was developed, and the isoureas thus obtained proved to be excellent reagents for the O-alkylation of carboxylic acids.  The usefulness of microwave irradiation to accelerate the esterification reactions was demonstrated.  The use of polymer-supported isoureas as intermediates in a catch-and-release esterification procedure was also investigated.

Some novel reactions of O-alkylisoureas were investigated in solution phase.  Alcohols could be O-benzylated using O-benzylisourea with Lewis acid catalysis.  Isoureas were used as reactive intermediates for the cyclisations of β-hydroxyamides to form 2-oxazolines and of N-hydroxyalkylsulfonamides to form cyclic sulfonamides.

Finally, a new activation mechanism for the reactions of isoureas using acetyl halides has been discovered, and applied to an efficient one-pot conversion of alcohols into haloalkanes.

University of Southampton
Crosignani, Stefano
aaa5cc3f-0b82-4d33-af01-59115c8bdff5
Crosignani, Stefano
aaa5cc3f-0b82-4d33-af01-59115c8bdff5

Crosignani, Stefano (2003) Studies on O-alkylisoureas in solution phase and on solid support. University of Southampton, Doctoral Thesis.

Record type: Thesis (Doctoral)

Abstract

The use of polymer-supported reagents is proving to be an ideal methodology for the clean and efficient preparation of chemical libraries.  Polymer-supported reagents for the oxidation of alcohols and for the O-alkylation of carboxylic acids were studied.  Several polymer-supported sulfoxides were prepared in order to accomplish catch-and-release oxidations of primary and secondary alcohols.  Unfortunately, an efficient protocol for the oxidations with purification of the intermediate polymer-supported sulfoxonium ion could not be achieved.

A protocol for the synthesis of polymer-supported O-alkylisoureas was developed, and the isoureas thus obtained proved to be excellent reagents for the O-alkylation of carboxylic acids.  The usefulness of microwave irradiation to accelerate the esterification reactions was demonstrated.  The use of polymer-supported isoureas as intermediates in a catch-and-release esterification procedure was also investigated.

Some novel reactions of O-alkylisoureas were investigated in solution phase.  Alcohols could be O-benzylated using O-benzylisourea with Lewis acid catalysis.  Isoureas were used as reactive intermediates for the cyclisations of β-hydroxyamides to form 2-oxazolines and of N-hydroxyalkylsulfonamides to form cyclic sulfonamides.

Finally, a new activation mechanism for the reactions of isoureas using acetyl halides has been discovered, and applied to an efficient one-pot conversion of alcohols into haloalkanes.

Text
914707.pdf - Version of Record
Available under License University of Southampton Thesis Licence.
Download (7MB)

More information

Published date: 2003

Identifiers

Local EPrints ID: 465120
URI: http://eprints.soton.ac.uk/id/eprint/465120
PURE UUID: a0e6541d-abe5-476d-befc-76903bc002e1

Catalogue record

Date deposited: 05 Jul 2022 00:24
Last modified: 16 Mar 2024 19:58

Export record

Contributors

Author: Stefano Crosignani

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×