Metal-free and enantioselective synthesis of 1,4-benzoxazepines from para-quinone methide derivatives and α-bromohydroxamates

Chem Commun (Camb). 2023 Jul 13;59(57):8822-8825. doi: 10.1039/d3cc02368k.

Abstract

A sequential asymmetric conjugate addition/cyclisation of α-bromohydroxamates with para-quinone methide derivatives has been developed, which provides enantioenriched 1,4-benzoxazepines in generally high yields (up to 95%) and good enantioselectivities (up to 97 : 3 er). This protocol not only offers a novel and straightforward strategy for constructing chiral 1,4-benzoxazepines, but also demonstrates the potential of α-bromohydroxamates as three-atom synthons in asymmetric cyclisation reactions.

MeSH terms

  • Cyclization
  • Indolequinones*
  • Stereoisomerism

Substances

  • quinone methide
  • Indolequinones