Three-step metal-promoted allene-based preparation of bis(heterocyclic) cyclophanes from carbonyl compounds

J Org Chem. 2014 Jul 3;79(13):6244-55. doi: 10.1021/jo500993x. Epub 2014 Jun 16.

Abstract

A straightforward metal-mediated method for the synthesis of bis(dihydrofuryl) cyclophane scaffolds from carbonyl compounds has been developed. The combination of the dihydrofuran moiety with different heterocycles such as β-lactams and sugars allows high levels of skeletal diversity. The process comprises indium-promoted one-pot carbonyl bis(allenylation) and gold- or palladium-catalyzed double cyclization in the resulting bis(allenols), followed by selective ruthenium-catalyzed macrocyclization. In some cases, the method has been successfully applied to the synthesis of the challenging Z-isomers. The E- versus Z-stereochemistry of the metathesis-formed double bonds could not be assigned taking into consideration the usual coupling constants criteria, but a diagnostic based on the chemical shifts of the two olefinic protons located at the macrocyclic double bond was established.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkenes / chemistry*
  • Catalysis
  • Cyclization
  • Ethers, Cyclic / chemical synthesis*
  • Ethers, Cyclic / chemistry
  • Furans / chemical synthesis*
  • Furans / chemistry
  • Gold / chemistry*
  • Macrocyclic Compounds / chemistry*
  • Molecular Structure
  • Palladium / chemistry*
  • Protons
  • Ruthenium / chemistry*
  • Stereoisomerism
  • beta-Lactams / chemical synthesis*
  • beta-Lactams / chemistry

Substances

  • Alkenes
  • Ethers, Cyclic
  • Furans
  • Macrocyclic Compounds
  • Protons
  • beta-Lactams
  • bis(dihydrofuryl)cyclophane
  • Palladium
  • Gold
  • Ruthenium