Palladium-catalyzed [4 + 2] cycloaddition of o-(silylmethyl)benzyl esters with ketones: an equivalent to oxo-Diels-Alder reaction of o-xylylenes

Org Lett. 2010 Oct 1;12(19):4332-4. doi: 10.1021/ol101792a.

Abstract

o-(Silylmethyl)benzyl carbonates reacted with various electron-deficient ketones in the presence of a palladium catalyst, affording the [4 + 2] cycloaddition products, isochromanes, in high yields. The palladium-catalyzed cycloaddition is equivalent to the oxo-Diels-Alder reaction of o-xylylene with ketones. The regioselectivities were extraordinarily affected by the structures of the o-xylylene precursors and ketones. The unusual regiochemistry may support two competitive reaction pathways in the catalytic reaction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Benzene / chemistry*
  • Catalysis
  • Cyclization
  • Esters / chemistry*
  • Ketones / chemistry*
  • Methylation
  • Molecular Structure
  • Palladium / chemistry*
  • Stereoisomerism
  • Xylenes / chemistry*

Substances

  • Esters
  • Ketones
  • Xylenes
  • Palladium
  • Benzene