Visible-Light-Mediated Radical Cascade Iodotrifluoroethylation and Acylation/Cyclization of N-Tethered 1,6-Enynes with 1,1,1-Trifluoro-2-iodoethane and Acyl Oxime Esters

Abstract

Photoinduced trifluoroethyl and acyl radical procedures for the efficient and simple preparation of iodotrifluoroethylated and acylated pyrrolidine-2-ones from N-tethered 1,6-enynes with 1,1,1-trifluoro-2-iodoethane and acyl oxime esters are reported. The photoinduced iodotrifluoroethylation is performed via the energy transfer (EnT) process of the fluorescein sodium-mediated atom-transfer radical addition (ATRA) strategy under visible-light irradiation. The acylation is carried out with 4CzIPN as an organophotocatalyst at room temperature under metal- and oxidant-free conditions. These methods provide a one-step, atom-economical route to produce a wide range of pyrrolidine-2-ones containing iodotrifluoroethyl and acyl groups with broad substrate scope and high selectivity.