Catalytic conjugate addition of heterocyclic compounds to α,β-unsaturated carbonyl compounds by hafnium salts and scandium salts
作者:Motoi Kawatsura、Sachiko Aburatani、Junichi Uenishi
DOI:10.1016/j.tet.2007.02.091
日期:2007.5
additions of heterocyclic compounds, such as indoles, pyrrole, pyrazole, and imidazole, have been demonstrated. Hafnium chloride effectively catalyzed the conjugate addition of indoles to α,β-unsaturated carbonyl compounds, and the addition product was obtained in high yield. The reaction of pyrrole was also catalyzed by HfCl4 or ScCl3, and produced 2,6-dialkylated pyrroles up to 99% yields. Furthermore
已经证明了氯化ha (HfCl 4)和氯化scan(ScCl 3)催化的杂环化合物(如吲哚,吡咯,吡唑和咪唑)的共轭加成。氯化有效地催化了吲哚与α,β-不饱和羰基化合物的共轭加成,并以高收率获得了加成产物。吡咯的反应也被HfCl 4或ScCl 3催化,并产生了2,6-二烷基化的吡咯,产率高达99%。此外,发生了吡唑和咪唑的1-位的共轭加成,并以良好的产率产生了几种取代的杂环化合物。