A three-component tandem Pd-catalyzed perfluoroalkylative borylation of terminal and internal alkynes is presented. On the basis of this methodology, the first reductive dicarbofunctionalization of alkynes with two electrophiles (perfluoroalkyl and aryl iodides) through a temperature-controlled sequence of iodoperfluoroalkylation–borylation coupling is developed. This regio- and stereoselective process is easily controllable by a temperature program, providing access to fluoroalkyl-substituted vinyl iodides, vinyl boronates, or olefins from the very same complex reaction mixture (four substrates, catalysts, base, and additives).

The highly toxic, inflammable, and odorless nature of CO causes problematic handling on laboratory-scale experiments. Replacement of CO cylinders by CO surrogates is particularly attractive, especially in the case of multicomponent reactions leading to valuable fluorinated products. We report a Pd-catalyzed three-component protocol for the direct synthesis of perfluoroalkyl-substituted α,β-unsaturated esters from acetylenes and perfluoroalkyl iodides, applying formates as convenient CO sources. The tandem reaction proceeds under mild conditions with excellent regio-and stereoselectivities toward the E-isomer (>95:5, E:Z). Detailed mechanistic investigations revealed that the process proceeds through an off-cycle, base-induced decomposition of formate to CO and phenoxide, which are reassembled on the Pd-center into an aryloxycarbonyl moiety, which is ultimately installed on the alkene scaffold. To complete the mechanistic picture of the reaction, the experimental study was supported by DFT calculations.