Nucleophilic Iododifluoromethylation of Carbonyl Compounds Using Difluoromethyl 2-Pyridyl Sulfone

A new, efficient method for iododifluoromethylation of carbonyl compounds utilizing difluoromethyl 2-pyridyl sulfone (2-PySO2CF2H) is described. This transformation is achieved by a nucleophilic addition of 2-PySO2CF2H with carbonyl compounds and a subsequent iodination of sulfinate, which is generated in situ by a novel zinc-mediated depyridination reaction. The method employs mild reaction conditions, exhibits excellent functional-group tolerance, and can be used in the synthesis of various iododifluoromethylated carbinols.