Copper-catalysed regiodivergent borocyanation of 2-substituted 1,3-dienes was achieved by a simple switch between two commercially available phosphine ligands. The reactions proceeded smoothly using N-cyano sulfonamides and B2pin2 as cyano and boron sources, respectively. Employing CuBrïSMe2/monodentate tricyclohexyl phosphine (PCy3) catalyst system, 1,2-borocyanated products were generated via unprecedented 1,4-borocupration, whereas 4,3-borocyanation products could also be provided through 4,1-borocupration by switching from PCy3 to the bidentate phosphine XantPhos. The first example of asymmetric copper-catalysed silylcyanation of 1,3-dienes has also been achieved with moderate yields and excellent enantioselectivities (up to 99% ee) and regioselectivities (up to >20:1 rs). The enantiometricly-enriched products of silylcyanation are valuable building blocks for organic synthesis and medicinal chemistry.
Date of Award | 1 Aug 2019 |
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Original language | English |
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Awarding Institution | - The University of Manchester
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Supervisor | David Procter (Supervisor) & Alexander Pulis (Supervisor) |
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Copper-Catalysed Borylative and Silylative Three-Component Coupling Reactions of 1,3-Dienes
He, Q. (Author). 1 Aug 2019
Student thesis: Master of Science by Research