Access to Difluoromethylated Alkynes through the Castro–Stephens Reaction. Issue 32 (30th September 2014)

• Record Type: Journal Article
• Authors: Besset, Tatiana; Poisson, Thomas; Pannecoucke, Xavier
• Is Part Of: European journal of organic chemistry. Issue 32(2014)
• Page Start: 7220
• Page End: 7225
• Publication Date: 2014-09-30
• Subjects: Synthetic methods -- Fluorine -- Alkynes -- Copper; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201402937
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract: An efficient synthesis of difluoromethylated alkynes is described. A panel of readily available Cu I acetylides undergo direct difluoromethylation by using BrCF2 CO2 Et, 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. Abstract : Based on a Castro–Stephens transformation, a coupling reaction between copper acetylides and inexpensive and readily available BrCF2 CO2 Et was developed. The approach offers straightforward access to a panel of synthetically valuable aryl, heteroaryl and alkyl difluoromethylated alkynes.