Synthesis of push-pull-activated ynol ethers and their evaluation in the bioorthogonal hydroamination reaction

Org Biomol Chem. 2022 Nov 30;20(46):9217-9221. doi: 10.1039/d2ob01917e.

Abstract

A new class of push-pull-activated alkynes featuring di- and trifluorinated ynol ethers was synthesized. The difluorinated ynol ether exhibited an optimal balance of stability and reactivity, displaying a substantially improved half-life in the presence of aqueous thiols over the previously reported 1-haloalkyne analogs while reacting just as fast in the hydroamination reaction with N,N-diethylhydroxylamine. The trifluorinated ynol ether reacted significantly faster, exhibiting a second order rate constant of 0.56 M-1 s-1 in methanol, but it proved too unstable toward thiols. These fluorinated ynol ethers further demonstrate the importance of the hyperconjugation-rehybridization effect in activating alkynes and demonstrate how substituent effects can both activate and stabilize alkynes for bioorthogonal reactivity.

Publication types

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

MeSH terms

  • Alkynes
  • Ether*
  • Ethers*
  • Sulfhydryl Compounds

Substances

  • Ethers
  • Ether
  • Alkynes
  • Sulfhydryl Compounds