Tandem Processes Identified from Reaction Screening: Nucleophilic Addition to Aryl <i>N</i>-Phosphinylimines Employing La(III)-TFAA Activation

Reaction screening of nucleophilic reaction partners for addition to N-diphenylphosphinylimines employing lanthanum(III) triflate as a catalyst and trifluoroacetic anhydride (TFAA) as an activator is reported. A number of tandem processes leading to novel chemotypes including aza-Prins/intramolecular Friedel−Crafts annulations have been identified, and both reaction scope and mechanism further investigated.