Deoxygenative functionalization of trifluoromethyl ketones.

A transition-metal-free deoxygenative functionalization of trifluoromethyl ketones via a Pudovik addition/phospha-Brook rearrangement sequence followed by benzylic substitution has been developed. The reaction proceeds under mild conditions to afford a variety of benzylic trifluoromethyl compounds in good yields. The method tolerates both electron-rich and halogen-substituted aromatic substrates, and accommodates diverse nucleophiles including amides, thiols, alkenes, and other heteroatom-based reagents. Mechanistic studies indicate that a benzyl phosphinate intermediate is formed through the phospha-Brook rearrangement and plays a pivotal role in facilitating the substitution step. This transformation offers a concise and efficient route to benzylic CF3 scaffolds from readily available trifluoromethyl ketones.