Pd-catalysed intramolecular transformations of indolylbenzenesulfonamides: ortho-sulfonamido-bi(hetero)aryls via C2-arylation and polycyclic sultams via C3 arylation

Org Biomol Chem. 2022 Nov 30;20(46):9148-9160. doi: 10.1039/d2ob01610a.

Abstract

Palladium-catalysed and base-dependent intra-molecular ipso-substitution and cyclisation strategies involving N-indolyl-substituted aryl-sulfonamides for the rapid construction of 2-aryl indole and indole-fused six-membered sultams are described. The Pd(OAc)2/Ph3P/Et3N combination delivers indolyl C2 arylated motifs via C(2)-N bond cleavage followed by C-C bond formation. In sharp contrast to this, the Pd(OAc)2/Ph3P/K2CO3 combination induced intramolecular-Heck cross-coupling affords polycyclic sultams exclusively. Thus, this strategy is completely additive-dependent. It also shows a broad substrate scope and delivers the corresponding products in good to high yields.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Indoles / chemistry
  • Naphthalenesulfonates*
  • Palladium* / chemistry

Substances

  • naphthosultone
  • Palladium
  • Naphthalenesulfonates
  • Indoles