Asymmetric phase transfer catalysed Michael additions and their application in synthesis

This thesis describes an investigation into organocatalysed asymmetric Michael additions and their application in synthesis. It focuses primarily on phase transfer catalysed processes, however other modes of catalysis are briefly investigated. Firstly, β-ketoesters derived from 1-indanone and l-tetr...

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Bibliographic Details
Main Author: Beynon, Christopher
Published: University of Nottingham 2012
Subjects:
Online Access:http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.588066
Description
Summary:This thesis describes an investigation into organocatalysed asymmetric Michael additions and their application in synthesis. It focuses primarily on phase transfer catalysed processes, however other modes of catalysis are briefly investigated. Firstly, β-ketoesters derived from 1-indanone and l-tetralone are examined as potential Michael donors. Their addition to methyl vinyl ketone is studied, with a view to producing members of the Gibberellin family. Secondly, the use of an achiral phenoxide "co-catalyst" in conjunction with a chiral quaternary ammonium salt, derived from cinchonidine, is found to produce an effective catalytic species. It is shown to promote the addition of benzophenone glycine imines to a range of Michael acceptors in excellent levels of enantiocontrol (>90% ee). The Michael adducts are then successfully converted to their corresponding 2,5-disubstituted pyrrolidine species, with high maintenance of stereocontrol. A potential application of this co-catalyst methodology is then described in studies towards the synthesis of kaitocephalin.