Chemo-, regio-, and stereoselective tetrafunctionalization of fluoroalkynes enables divergent synthesis of 5-7-membered azacycles

Palladium-Catalyzed Regioselective Monofluoroallylation of Indoles with gem-Difluorocyclopropanes

We present a palladium-catalyzed ring-opening reaction that induces indoles to cross-couple with gem-difluorocyclopropanes. The reaction proceeds through a domino process of C-C bond activation and C-F bond elimination, followed by C-C(sp2) coupling to produce various 2-fluoroallylindoles. This method is characterized by its high functional group tolerance, good yields and high regioselectivity, under base-free conditions. The synthetic utility of the products is illustrated by the functionalization of the NH and C2 positions of the indole scaffold.

Silver-Promoted Three-Component Synthesis of Perfluoroalkenyl Pyrroles through Partial Defluorinative Functionalization of Perfluoroalkyl Halides

A silver-promoted three-component heterocyclization of alkynes, perfluoroalkyl halides, and 1,3-dinucleophiles was developed for the efficient synthesis of privileged (E)-perfluoroalkenyl pyrroles. The reaction proceeded through a rationally designed sequence of radical perfluoroalkylation and intramolecular defluorinative [3 + 2]-heterocyclization. The utility of perfluoroalkyl halide as a perfluoroalkenyl reagent, by selective and controllable functionalization of two inert C(sp3)-F bonds at vicinal carbon centers on the perfluoroalkyl chain, provides a new reaction mode for the synthesis of value-added organofluorides starting from the easily available and low-cost fluorinated feedstock.