Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.553314
Title: α-Arylation of lithiated N-allyl ureas
Author: Tetlow, Daniel John
Awarding Body: University of Manchester
Current Institution: University of Manchester
Date of Award: 2011
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Abstract:
The synthesis of amines bearing an adjacent quaternary stereocentre is challenging. Work within our group has demonstrated that the intramolecular transfer of an aryl group within a lithiated benzylic urea is possible. Subsequent cleavage of this urea moiety allows the synthesis of chiral aryl amines bearing quaternary stereocentres. This thesis details investigations into the lithiation of allylic and vinylic ureas. A sequential transformation of allyl ureas into diarylallyl ureas has been developed, a reaction that can be carried out enantioselectively using chiral lithium amides. Deprotection of the urea allows for the isolation of amines bearing highly substituted centres. It has been shown that the use of the acid-labile vinylic protecting groups allows the corresponding Cbz protected diarylallyl amines to be synthesised. Investigations have demonstrated that these analogues can be converted into otherwise synthetically challenging diarylglycine derivatives. During these investigations it has also been shown that carbolithiation of vinyl ureas is possible. The ureas formed from this tandem β-alkylation/α-arylation sequence can then be converted to their highly substituted amine counterparts in good yields. A range of allylic ureas has been investigated; their synthesis and reactivity upon lithiation are discussed within this thesis.
Supervisor: Clayden, Jonathan Sponsor: AstraZeneca ; EPSRC
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.553314  DOI: Not available
Keywords: Allyl Lithium ; a-Arylation ; Highly Substituted Amines
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