Trifluoroacetaldehyde N-tosylhydrazone as reagent for trifluoroethylation of terminal alkynes

Abstract

Application of trifluoroacetaldehyde N-tosylhydrazone as a new trifluoroethylating reagent for terminal alkynes is reported. This compound acts as an analog of 2,2,2-trifluorodiazoethane, devoid of such drawbacks as volatility, toxicity, storage instability, and explosion hazard. The CuI-catalyzed C-H insertion reaction of trifluoroacetaldehyde Ntosylhydrazone into terminal alkynes demonstrated its broad applicability in the synthesis of trifluoroethyl-substituted acetylenes under mild basic conditions. This method provides high yields and compatibility with a wide range of functional groups.2