α-Vinylation of 1,3-Dicarbonyl Compounds with Alkenyl(aryl)iodonium Tetrafluoroborates: Effects of Substituents on the Aromatic Ring and of Radical Inhibitors
作者:Masahito Ochiai、Toshifusa Shu、Takema Nagaoka、Yutaka Kitagawa
DOI:10.1021/jo962007y
日期:1997.4.1
1,3-dicarbonyl compounds with 4-tert-butyl-1-cyclohexenyl(aryl)iodonium 2 and 1-cyclopentenyl(aryl)iodonium tetrafluoroborates 3 are reported. Frequently, alpha-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 alpha-vinylation at the
据报道,由1,3-二羰基化合物与4-叔丁基-1-环己烯基(芳基)碘鎓2和1-环戊烯基(芳基)碘鎓四氟硼酸酯3衍生的烯醇酸根阴离子的直接α-乙烯基化。通常,在1,3-二羰基化合物与烯基(苯基)碘鎓盐2a和3a的反应中,α-苯基化与乙烯基化竞争。然而,烯基(对甲氧基苯基)碘鎓盐2b和3b的使用导致选择性的α-乙烯基化,以1,3-二羰基化合物的竞争性芳基化为代价。使用有效的芳基自由基捕集剂1,1-二苯基乙烯可抑制自由基诱导的烯基(芳基)碘鎓盐分解,从而提高衍生自1,3-二羰基化合物的烯醇式阴离子的α-乙烯基化的收率。