Silicon holds a privileged position in organic chemistry as the carbon-silicon bond can be utilised in many important transformations. As such, developing practical and efficient methods for the enantioselective and regioselective insertion of silicon into organic molecules is a worthy challenge in chemical synthesis. To this end, we have developed an affordable copper-catalysed protocol for the asymmetric silylation of lactones, lactams and amides, providing silylated products with up to > 99:1 er and in good yields. Furthermore, we have demonstrated the synthetic utility of this protocol in the target synthesis of natural or biologically active molecules. We also present the first copper-catalysed silylation of allenes using a silylborane reagent. This affords useful allyl- or vinylsilane building blocks with high regioselectivity, efficiency and a large functional group tolerance. The allylcopper intermediates can be intercepted by aldehydes in a diastereoselective three-component coupling to furnish homoallylic alcohols. We extend this concept to the copper-catalysed three-component coupling of boron, allenes and imines, providing access to homoallylic amines with a vinylborane motif.
Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:727830 |
Date | January 2015 |
Creators | Rae, James |
Contributors | Procter, David |
Publisher | University of Manchester |
Source Sets | Ethos UK |
Detected Language | English |
Type | Electronic Thesis or Dissertation |
Source | https://www.research.manchester.ac.uk/portal/en/theses/coppercatalysed-silicon-and-boron-functionalisation-of-heterocycles-and-allenes(a86718c0-18b4-4092-a2bd-b978797153db).html |
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