Journal of Saudi Chemical Society (Nov 2022)

Divergent synthesis of fused Benzo-xanthene and oxazine derivatives via Cu-catalyst

  • Meshari A Alsharif,
  • Naseem Ahmed,
  • Mohammed Issa Alahmdi,
  • Sayeed Mukhtar,
  • Humaira Parveen,
  • Rami J. Obaid,
  • Abdulraheem S.A. Almalki

Journal volume & issue
Vol. 26, no. 6
p. 101568

Abstract

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Cu-Cu2O combination showed synergic effects in catalyzing intramolecular Ullmann coupling reaction for halo-Betti bases to afford fused benzo-xanthenes from both electron-rich and electron-deficient aromatic systems in good yield under mild reaction conditions. The sterically hindered halo-Betti bases also provided products in excellent yield. Under optimized condition, a gram scale reaction was also performed to afford the product in excellent yield. However, without ortho-halo substituted Betti-bases failed to afford fused benzo-xanthene derivatives. Exploring the reaction optimization without Cu metal, serendipitously it was produced 1,3-oxazine derivatives in excellent yield via intramolecular cross-dehydrogenative coupling (CDC) reaction. Similarly, electron-rich, electron-deficient and sterically hindered Betti-bases provided the products in good to excellent yield under mild condition.

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