1 - Memorial University of Newfoundland

2.4.2 General EXI)Crimental Procedures
2.4.2.1 General Experimental Procedure A: Preparation of Po\'arov adducts using
the three-component reaction
To a clear, colorless solution of 3-aminocoumarin in acetonitrile (- 0.1 M
solution) were added the aldehyde (1.05 equiv). Yb(OTf)) (5 mol %) and the dienophile
(3.0 equiv). The reaction mix lure was slirred al room Icmperature or healed at renux as
specified. The reaction was monitored by tic until Ihe complele consumption of 3­
aminocoumarin occured. The solvent was removed under reduced pressure and the
residue was subjecled to nash chromatography. The isolated produci was then
rccryslallized from the appropriate solvent(s). The dr was detennined from IH NMR
analysis of the crude reaction mixture.
2.4.2.2 General Experimental Procedure B: PrCIJUration of Povarov adducts using
modified conditions for the threc-component reaction
To a clear, colorless solution of 3-aminocoumarin in acetonitrile (- 0.1 M
solution) were added the aldehyde (1.05 equiv), Yb(OTf)) (10 mol %) and the dienophile
(3.0 cquiv). The reaction mixture was stirred at room tcmpeT:lIUre or heatcd at reflux as
specificd for individual reactions. The reaction was monitored by lie until the complcte
consumption of 3-aminocoumarin occured. The solvent was removed undcr reduced
pressure and the residue was subjected to nash chromatography. The isolated product
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