Transition-Metal-, Additive-, and Solvent-Free [3 + 3] Annulation of RCF 2 -Imidoyl Sulfoxonium Ylides with Cyclopropenones to Give Multifunctionalized CF 3 -Pyridones.

An efficient and practical strategy was developed to synthesize 1,3,4-triaryl-6-trifluoromethylpyridones from CF 3 -imidoyl sulfoxonium ylides and cyclopropenones in good to excellent yields. This stepwise [3 + 3] annulation reaction was carried out under transition-metal-, additive-, and solvent-free conditions, generating 1 equiv of dimethyl sulfoxide as byproduct and tolerating a series of functional groups.