Synthesis of α‐Trifluoromethylthiolated and α‐Thiocyanated Ketones Using Umpoled Enolates

An efficient synthesis of α‐trifluoromethylthiolated and α‐thiocynated ketones via Umpolung strategy is developed. Umpoled enolates (N‐alkenoxypyridinium salts) react smoothly with readily available sulfur containing nucleophiles such as AgSCF3 and KSCN using CH3CN as the solvent. N‐alkenoxypyridinium salts could be easily prepared from the gold catalyzed addition of pyridine N‐oxide to alkynes. Our simple condition offers good chemical yields and high functional group tolerance.