Visible-Light-Induced α-Trifluoromethylation of Unactivated α,β-Unsaturated Carbonyl Compounds: Pyruvic Acid as an Additive

Herein, we report a visible-light-induced α-trifluoromethylation of α,β-unsaturated carbonyl compounds using Langlois reagent (CF3SO2Na) as the trifluoromethyl source and pyruvic acid (PA) as an additive. This metal- and photocatalyst-free protocol exhibits a broad substrate scope, affording the desired products in isolated yields ranging from 34% to 79%. This method was further applied to the synthesis of LTZ-8, a drug candidate for benign prostatic hyperplasia (BPH).