Pd-Catalyzed Arylation of Secondary α-Alkoxytricyclohexylstannanes

Org Lett. 2022 Dec 2;24(47):8714-8718. doi: 10.1021/acs.orglett.2c03729. Epub 2022 Nov 18.

Abstract

We have developed a general process for the formation of α-arylethers via the Pd-catalyzed arylation of secondary α-alkoxytricyclohexylstannanes. Incorporation of cyclohexyl spectator ligands into the alkylstannane and the use of the electron-deficient ligand JackiePhos (1) are critical for achieving selective alkyl transfer in this process. This system circumvents the need for a coordinating/directing oxygen-protecting group to promote selective alkyl transfer and enables α-tetrahydropyran, α-tetrahydrofuran, and open-chain secondary α-alkoxy groups to be employed efficiently in Pd-catalyzed Stille reactions with a broad range of aryl electrophiles. These findings suggest that selective transmetalation of a single marginally activated secondary alkyl unit from Sn to Pd should be broadly achievable provided that unactivated secondary alkyl ligands comprise the other three groups of the tetraalkylstannane.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkylation
  • Electrons*
  • Ligands
  • Oxygen
  • Palladium*

Substances

  • Ligands
  • Palladium
  • Oxygen