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Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides
Published on: May 26, 2019
Programmed Sequential Additions to Halogenated Mucononitriles
Adam J Zahara1, Elsa M Hinds1, Andrew L Nguyen1
1Department of Chemistry, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States.
Abstract:
Dihalomucononitriles were synthesized and their reactivity evaluated to assess their ability to function as linchpin reagents. Bis(2-chloroacrylonitrile) and bis(2-bromoacrylonitrile) were synthesized from 2,1,3-benzothiadiazole and undergo conjugate addition/elimination reactions with both nitrogen (40-95% yield) and carbon nucleophiles (72-93% yield). Secondary amines undergo monosubstitutions, while carbon nucleophiles are added twice. The sequence of addition of the nucleophiles could be controlled to give mixed addition products. The multicomponent coupling products could then be converted to natural product like motifs using intramolecular cyclization reactions.
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