Electrolytic partial fluorination of organic compounds. 3. Regioselective anodic monofluorination of organoselenium compounds and their synthetic application
Regioselectiveanodic α-monofluorination of selenides bearing electron-withdrawing groups such as cyano, ester, and amide groups was successfully performed. Highly stereoselective synthesis of α-fluoro α,β-unsaturated esters was achieved by using an α-fluoro α-selenoester prepared.
The scandium-catalyzed reactions of alpha-organosulfanyl and organoselanyl-alpha-fluoroacetates 1-2, acetamides 3-4 and acetonitrile 5 with soft nucleophiles proceeded to give the products 6a-b, 7a-c, 8a-c, 9a-e in good to high yields. We also successfully performed the scandium-catalyzed intramolecular cyclization reactions and obtained the unique 5-methylene-2-oxotetrahydropyrans 16-17.