Combined directed ortho and remote metalation-Suzuki cross-coupling strategies. Efficient synthesis of heteroaryl-fused benzopyranones from biaryl O-carbamates

J Org Chem. 2009 Jun 5;74(11):4094-103. doi: 10.1021/jo900146d.

Abstract

A concise synthesis of heteroaryl dibenzopyranones 9a,b, 10a,b, 11a-c, and 12a-c has been achieved by the LDA-induced migration of heterobiaryl O-carbamates 18, 21, 25, and 30 which, in turn, were prepared in good yield using a combined directed ortho lithiation (DoM)-transition-metal-catalyzed Suzuki cross-coupling strategy. An efficient and general route to a wide variety of heterocycles including coumestans 19a,c and the previously unknown isothiocoumestan ring system 22b has been thereby achieved.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzopyrans / chemical synthesis*
  • Carbamates / chemistry*
  • Coumarins / chemical synthesis*
  • Heterocyclic Compounds / chemical synthesis*
  • Metals / chemistry
  • Organic Chemistry Phenomena

Substances

  • Benzopyrans
  • Carbamates
  • Coumarins
  • Heterocyclic Compounds
  • Metals
  • coumestan