Synthesis of Chlorotrifluoromethylated Pyrrolidines by Electrocatalytic Radical Ene-Yne Cyclization

The stereoselective synthesis of chlorotrifluoromethylated pyrrolidines was achieved using anodically coupled electrolysis, an electrochemical process that combines two parallel oxidative events in a convergent and productive manner. The bench-stable and commercially available solids CF3SO2Na and MgCl2 were used as the functional group sources to generate CF3. and Cl-., respectively, via electrochemical oxidation, and the subsequent reaction of these radicals with the 1,6-enyne substrate was controlled with an earth-abundant Mn catalyst. In particular, the introduction of a chelating ligand allowed for the ene-yne cyclization to take place with high stereochemical control over the geometry of the alkene group in the pyrrolidine product.