The Synthesis of Spirocycles via C–H Insertion

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Author(s)
Primary Supervisor
Coster, Mark
Other Supervisors
Poulsen, Sally-Ann
Year published
2016
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This thesis describes the design and development of a new methodology for the synthesis of spiroacetals involving a rhodium(II)-catalysed C–H insertion of suitable diazo precur- sors. Three generations of diazo precursors were designed, synthesised and treated with Rh(II) catalysts:
The 1st generation precursor consisted of a phenyl substituted tetrahydropyranyl acetal bearing a proximal phenyl diazoketone substituent, which underwent Rh(II)-catalysed C– H insertion to give unexpected spirocyclic orthoesters. DFT calculations showed that these ’anomalous’ products are formed by a mechanism involving hydride transfer to the ...
View more >This thesis describes the design and development of a new methodology for the synthesis of spiroacetals involving a rhodium(II)-catalysed C–H insertion of suitable diazo precur- sors. Three generations of diazo precursors were designed, synthesised and treated with Rh(II) catalysts: The 1st generation precursor consisted of a phenyl substituted tetrahydropyranyl acetal bearing a proximal phenyl diazoketone substituent, which underwent Rh(II)-catalysed C– H insertion to give unexpected spirocyclic orthoesters. DFT calculations showed that these ’anomalous’ products are formed by a mechanism involving hydride transfer to the rhodium carbene followed by intramolecular C–O bond formation.
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View more >This thesis describes the design and development of a new methodology for the synthesis of spiroacetals involving a rhodium(II)-catalysed C–H insertion of suitable diazo precur- sors. Three generations of diazo precursors were designed, synthesised and treated with Rh(II) catalysts: The 1st generation precursor consisted of a phenyl substituted tetrahydropyranyl acetal bearing a proximal phenyl diazoketone substituent, which underwent Rh(II)-catalysed C– H insertion to give unexpected spirocyclic orthoesters. DFT calculations showed that these ’anomalous’ products are formed by a mechanism involving hydride transfer to the rhodium carbene followed by intramolecular C–O bond formation.
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Thesis Type
Thesis (PhD Doctorate)
Degree Program
Doctor of Philosophy (PhD)
School
School of Natural Sciences
Copyright Statement
The author owns the copyright in this thesis, unless stated otherwise.
Item Access Status
Public
Subject
Spiroacetals
C–H insertion
Phenyl substituted tetrahydropyranyl
Rhodium(II)-catalysed C–H insertion