Access to difluoromethylated alkynes through the castro-stephens reaction

Article abstract of DOI:10.1002/ejoc.201402937

An efficient synthesis of difluoromethylated alkynes is described. A panel of readily available Cu^I acetylides undergo direct difluoromethylation by using BrCF₂CO₂Et, which is an inexpensive, easy to handle, commercially available fluorinated reagent. The reaction, which is based on a Castro-Stephens transformation, proceeds smoothly under mild conditions offering a new synthetic route for the direct introduction of the difluoromethylated group into alkynes that does not involve ozone-depleting reagents. The resulting products were obtained with good yields by using CsOPiv and Cu(OAc)₂ as additives.