Catalyst and substrate effects in enantioselective C–H insertion reactions of α-diazosulfones

Clarke, Leslie-Ann

Restricted to everyone for five years. Restriction lift date: 2021-09-29T09:22:54Z

Catalyst and substrate effects in enantioselective C–H insertion reactions of α-diazosulfones

dc.check.date	2021-09-29T09:22:54Z
dc.check.embargoformat	Both hard copy thesis and e-thesis	en
dc.check.entireThesis	Entire Thesis Restricted
dc.check.info	Restricted to everyone for five years	en
dc.check.opt-out	Not applicable	en
dc.check.reason	This thesis is due for publication or the author is actively seeking to publish this material	en
dc.contributor.advisor	Maguire, Anita R.	en
dc.contributor.author	Clarke, Leslie-Ann
dc.contributor.funder	Irish Research Council	en
dc.date.accessioned	2016-09-30T09:22:54Z
dc.date.issued	2015
dc.date.submitted	2015
dc.description.abstract	This thesis describes a systematic investigation of the mechanistic and synthetic aspects of intramolecular reactions of a series of α-diazo-β-oxo sulfone derivatives using copper and, to a lesser extent, rhodium catalysts. The key reaction pathways explored were C–H insertion and cyclopropanation, with hydride transfer competing in certain instances. Significantly, up to 98% ee has been achieved in the C–H insertion processes using copper-NaBARF-bisoxazoline catalysts, with the presence of the additive NaBARF critical to the efficiency of the transformations. This novel synthetic methodology provides access to a diverse range of enantioenriched heterocyclic compounds including thiopyrans, sulfolanes, β- and γ-lactams, in addition to carbocycles such as fused cyclopropanes. The synthesis of the α-diazosulfones required for subsequent investigations is initially described. Of the twenty seven diazo sulfones described, nineteen are novel and are fully characterised in this work. The discussion is subsequently focused on a study of the copper and rhodium catalysed reactions of the α-diazosulfones with Chapter Four concentrated on highly enantioselective C–H insertion to form thiopyrans and sufolanes, Chapter Five focused on C–H insertion to form fused sulfolanes, Chapter Six focused on C–H insertion in sulfonyl α-diazoamides where both lactam formation and / or thiopyran / sulfolane formation can result from competing C–H insertion pathways, while Chapter Seven focuses on cyclopropanation to yield fused cyclopropane derviatives. One of the key outcomes of this work is an insight into the steric and / or electronic factors on both the substrate and the catalyst which control regio-, diastereo- and enantioselectivity patterns in these synthetically powerful transformations. Full experimental details for the synthesis and spectral characterisation of the compounds are included at the end of each Chapter, with details of chiral stationary phase HPLC analysis and assignment of absolute stereochemistry included in the appendix.	en
dc.description.status	Not peer reviewed	en
dc.description.version	Accepted Version
dc.format.mimetype	application/pdf	en
dc.identifier.citation	Clarke, L .A. 2015. Catalyst and substrate effects in enantioselective C–H insertion reactions of α-diazosulfones. PhD Thesis, University College Cork.	en
dc.identifier.endpage	581	en
dc.identifier.uri	https://hdl.handle.net/10468/3139
dc.language.iso	en	en
dc.publisher	University College Cork	en
dc.rights	© 2015, Leslie Ann Clarke.	en
dc.rights.uri	http://creativecommons.org/licenses/by-nc-nd/3.0/	en
dc.subject	Diazosulfone	en
dc.subject	C-H insertion	en
dc.subject	Asymmetric catalysis	en
dc.thesis.opt-out	false
dc.title	Catalyst and substrate effects in enantioselective C–H insertion reactions of α-diazosulfones	en
dc.type	Doctoral thesis	en
dc.type.qualificationlevel	Doctoral	en
dc.type.qualificationname	PhD (Science)	en
ucc.workflow.supervisor	a.maguire@ucc.ie