A study of palladium catalyzed intra/intermolecular cascade cross coupling/cyclizations involving bicyclopropylidene

Molecules. 2014 May 13;19(5):6058-69. doi: 10.3390/molecules19056058.

Abstract

The compounds [3-(2-Bromocyclohex-2-enyloxy)prop-1-ynyl]-tert-butyl-dimethylsilane 3, [4-(2-bromocyclohex-2-en-1-yloxy)but-2-yn-1-yloxy]tert-butyldimethylsilane 5 and dimethyl 2-(2-bromocyclohex-2-enyl)-2-(3-(tert-butyldimethylsilanyl)prop-2-ynyl)malonate 9 were prepared and subjected to palladium-catalyzed intra-intermolecular cascade cross couplings incorporating bicyclopropylidene 10 under two types of conditions. In the presence of Pd(OAc)2, PPh3 and K2CO3 in acetonitrile at 80 °C, the products were indene analogues, cross-conjugated tetraenes 11, 12 and 13, respectively. The corresponding spirocyclopropanated tricycle 16 in dimethylformamide at 110 °C was obtained, albeit in low yield (24%), and observed as an equimolar mixture of diastereomers, whereas 14, 15 were not fully isolated.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Catalysis
  • Cyclization* / drug effects
  • Cyclohexanones / chemical synthesis
  • Cyclohexanones / chemistry*
  • Molecular Structure
  • Palladium / chemistry*
  • Silanes / chemistry
  • Stereoisomerism

Substances

  • 2-bromocyclohexanone
  • Cyclohexanones
  • Silanes
  • tert-butyldimethylsilane
  • Palladium