α-Vinylation of 1, 3-Dicarbonyl Compounds with Alkenyl (aryl) iodonium Tetrafluoroborates: Effects of Substituents on the Aromatic Ring and of Radical Inhibitors
Direct α-vinylations of enolate anions derived from 1, 3-dicarbonyl compounds with 4-tert- butyl-1-cyclohexenyl (aryl) iodonium 2 and 1-cyclopentenyl (aryl) iodonium tetrafluoroborates 3 are reported. Frequently, α-phenylations compete with the vinylations in the reaction of 1, 3-dicarbonyl compounds with alkenyl (phenyl) iodonium salts 2a and 3a. Use of alkenyl (p-methoxyphenyl) iodonium salts 2b and 3b, however, leads to selective α ...