Hydroamination of 2-Ethynyl-4,5,6,7-tetrahydroindoles: Toward 2-Substituted Amino Derivatives of Indole
作者:Boris Trofimov、Lyubov’ Sobenina、Denis Tomilin、Ol’ga Petrova、Igor’ Ushakov、Al’bina Mikhaleva
DOI:10.1055/s-0029-1218768
日期:2010.7
Hydroamination of 1-phenyl-3-(4,5,6,7-tetrahydro-1H-indol-2-yl)prop-2-yn-1-ones with secondary dialkylamines proceeds under mild conditions (room temperature, aqueous ethanol, 1 h) to afford the corresponding (2E)-3-dialkylamino-3-(4,5,6,7-tetrahydro-1H-indol-2-yl)prop-2-en-1-ones in 72-92% stereoselectivity and 64-88% yield. Under the same conditions, ethyl 3-(4,5,6,7-tetrahydro-1H-indol-2-yl)prop-2-ynoates react with dimethylamine and diethylamine in different ways; dimethylamine converts the ester function into an amide, giving the corresponding N,N-dimethyl-3-(4,5,6,7-tetrahydro-1H-indol-2-yl)prop-2-ynamides in 70-86% yield, whereas diethylamine adds to the triple bond to give the corresponding ethyl 3-(diethylamino)-3-(4,5,6,7-tetrahydro-1H-indol-2-yl)prop-2-enoates with ∼100% stereoselectivity and up to 85% yield. The difference in the reactivity of the two amines can be rationalized in terms of steric hindrance.
在温和的条件下(室温,乙醇水溶液,1 小时),1-苯基-3-(4,5,6,7-四氢-1H-吲哚-2-基)丙-2-炔-1-酮与仲二烷基胺发生氢化反应,得到相应的(2E)-3-二烷基氨基-3-(4,5,6,7-四氢-1H-吲哚-2-基)丙-2-烯-1-酮,立体选择性为 72-92%,产率为 64-88%。在相同条件下,3-(4,5,6,7-四氢-1H-吲哚-2-基)丙-2-炔酸乙酯与二甲胺和二乙胺的反应方式不同;二甲基胺将酯功能转化为酰胺,得到相应的 N,N-二甲基-3-(4,5,6,7-四氢-1H-吲哚-2-基)丙-2-炔酰胺,产率为 70-86%、而二乙胺与三键结合生成相应的 3-(二乙氨基)-3-(4,5,6,7-四氢-1H-吲哚-2-基)丙-2-烯酸乙酯,立体选择性为 100%,产率高达 85%。这两种胺的反应性差异可以从立体阻碍的角度得到合理解释。