Zn(II)- or Ag(I)-Catalyzed 1,4-Metathesis Reactions between 3‑En-1-ynamides and Nitrosoarenes

Catalyst-dependent metathesis reactions
between 3-en-1-ynamides
and nitrosoarenes are described. Particularly notable are the unprecedented
1,4-metathesis reactions catalyzed by Ag­(I) or Zn­(II) to give 2-propynimidamides
and benzaldehyde derivatives. With 3-en-1-ynamides bearing a cycloalkenyl
group, 1,4-oxoimination products were produced efficiently. We have
developed metathesis/alkynation cascades for unsubstituted 2-propynimidamides
and benzaldehyde species generated in situ, to manifest
1,4-hydroxyimination reactions of 3-en-1-ynes. Both 1,4-oxoiminations
and 1,4-hydroxyiminations increase the molecular complexity of products.