Ruthenium-Catalyzed Alkylation of Indoles with Tertiary Amines by Oxidation of a sp<sup>3</sup>CH Bond and Lewis Acid Catalysis
作者:Ming-Zhong Wang、Cong-Ying Zhou、Man-Kin Wong、Chi-Ming Che
DOI:10.1002/chem.200902387
日期:2010.5.17
catalysts for direct C‐3 alkylation of indoles, giving the desired products in high yields (up to 82 % based on 60–95 % substrate conversions). These ruthenium compounds catalyze oxidative coupling reactions of a wide variety of anilines and indoles bearing electron‐withdrawing or electron‐donating substituents with high regioselectivity when using tBuOOH as an oxidant, resulting in the alkylation of N‐arylindoles
钌卟啉(特别是[Ru(2,6-Cl 2 tpp)CO]; tpp =四苯基卟啉)和RuCl 3可以作为氧化和/或路易斯酸催化剂,用于吲哚的直接C-3烷基化,从而以高纯度得到所需的产物收率(基于60–95%的底物转化率,最高可达82%)。当使用t BuOOH作为氧化剂时,这些钌化合物催化具有高区域选择性的带有吸电子或给电子取代基的各种苯胺和吲哚的氧化偶联反应,导致N-芳基吲哚烷基化为3-[[[ N -芳基-N-烷基)氨基]甲基}吲哚(收率:最高82%,转化率:最高95%)和N的烷基化-烷基或N -H吲哚成3- [对-(二烷基氨基)苄基]吲哚(收率:最高73%,转化率:最高92%)。提议涉及两个途径的暂定反应机理:可以由SP的氧化而生成的中间亚胺离子3 Ç 由oxoruthenium物种的烷基化苯胺的H键; 然后该亚胺离子可能被N-芳基吲哚捕获(途径A)或转化为甲醛,随后在路易斯的存在下,原