Direct Assembly of 3,4‐Difunctionalized Benzofurans and Polycyclic Benzofurans by Phenol Dearomatization and Palladium‐Catalyzed Domino Reaction

Abstract

A method to directly convert 2‐alkynylphenols to 3,4‐difunctionalized benzofurans and polycyclic benzofurans was developed. This protocol involves a hypervalent‐iodine‐mediated oxidative dearomatization to break the aromaticity of 2‐alkynylphenols, and a palladium‐catalyzed domino reaction to install two functional groups at the C3 and the C4 positions and restore the aromaticity of benzofurans.

Heterotetracenes: Flexible Synthesis and in Silico Assessment of the Hole‐Transport Properties

“…[9] To improve synthetic efficiency and allow functionalization at less-reactive positions, domino reactions constitutea na ttractive strategy. [10] For example, the formation of the heterocycle and another CÀCb ond at the C3 position was employed to synthesize alkenyl-, aryl-or alkyl-C3-substituted benzofurans using Pd [11] or Rh [12] catalysis, and C3 alkyl or aryl benzothiophenes and benzofurans through Au/Pt [13] or Pd [14] catalysis. To our surprise, ac yclization-alkynylation domino process was unprecedented.…”

Facile Access to Benzofuran Derivatives through Radical Reactions with Heteroatom-centered Super-electron-donors

“…To date, a diversity of synthetic approaches have been developed for e cient construction of 3functionalized benzofuran molecules (Figure 1b). [10][11][12][13][14][15][16] Early in the 1950s, Whitaker and co-workers have developed an acid-promoted dehydrative cyclization process of electron-rich o-hydroxybenzylketones for access to a series of 3-substituted benzofuran molecules bearing a 5-phenylsulfonylamino group (eq. 1).…”