An Ir-Pt Catalyst for the Multistep Preparation of Functionalized Indoles from the Reaction of Amino Alcohols and Alkynyl Alcohols
作者:Alessandro Zanardi、Jose A. Mata、Eduardo Peris
DOI:10.1002/chem.201001180
日期:2010.11.22
combination of an iridium‐mediated oxidative cyclization of 2‐(ortho‐aminophenyl)ethanol to form indoles, with a further step employing a Pt‐based multistep reaction that functionalizes indoles. Our results show that the Ir–Pt complex is a very active catalyst in this new multistep preparation of functionalized indolesfrom the reaction of an amino alcohol with alkynyl alcohols.
the multistep reaction of N-methyl indole (1 a) with pent-3-yn-1-ol (2 a) in THF at roomtemperature for 2 h to give indole derivative 3 a, which contains a five-membered cyclicether group at C3 in 93% yield. Under similar reaction conditions, various substituted N-methyl indoles 1 b-h and indole (1 i) reacted efficiently with 2 a to afford the corresponding indole derivatives 3 b-h and 3 i in 48-91
PtCl2在室温下有效催化N-甲基吲哚(1a)与戊-3-炔-1-醇(2a)在THF中的多步反应2小时,得到吲哚衍生物3a,其中包含五元C3的环醚基产率为93%。在相似的反应条件下,各种取代的N-甲基吲哚1bh和吲哚(1i)与2a有效反应,以48-91的产率和72%的产率得到相应的吲哚衍生物3bh和3i。结果表明,具有给电子取代基的N-甲基吲哚比具有吸电子基团的那些具有更高的反应活性,提供了更高的产率。同样地,各种取代的but-3-yn-1-ols 2 be和其他长链炔醇2 fi也与N-甲基吲哚(1 a)进行环化加成反应,以提供相应的环化加成产物3 jm和3 a ,3 j和3 no的收率良好至优异。本发明的铂催化的环化-加成反应可以进一步扩展到N-甲基吡咯中。从机理上讲,催化反应是通过炔醇的分子内加氢烷氧基化反应得到环状烯醇醚,然后将吲哚的CH键加到环状烯醇醚的不饱和部分上而提供最终产物。提
Bis-cyclometallated gold(iii) complexes as efficient catalysts for synthesis of propargylamines and alkylated indoles
作者:Hok-Ming Ko、Karen Ka-Yan Kung、Jian-Fang Cui、Man-Kin Wong
DOI:10.1039/c3cc44828b
日期:——
Stable bis-cyclometallated gold(III) complexes were developed as efficient catalysts for organic transformation reactions by using two strategies: (1) construction of distorted square planar gold(III) complexes and (2) dual catalysis by gold(III) complexes and silver salts.
Thorpe–Ingold effect in copper(II)-catalyzed formal hydroalkoxylation–hydroarylation reaction of alkynols with indoles
作者:Nitin T. Patil、Vivek S. Raut、Rahul D. Kavthe、Vaddu V.N. Reddy、P.V.K. Raju
DOI:10.1016/j.tetlet.2009.09.057
日期:2009.11
The use of Cu(OTf)(2) as a catalyst for tandem hydroalkoxylation-hydroarylation reaction of alkynes tethered with hydroxyl group is reported. The reaction proceeds at 60 degrees C or even at room temperature with 5 mol% catalyst loading and produces C-3-substituted indoles in good to high yields. The method was shown to be applicable to a broad range of indoles, containing electron-withdrawing and electron-donating substituents, and alkynol substrates bearing sterically demanding substituents in the tether. Interestingly, it was found that Thorpe-Ingold effect is operating for this cyclization reaction. Easy availability and low cost of Cu(OTf)(2) make this method attractive and amenable for large-scale synthesis compared to known literature methods. (C) 2009 Published by Elsevier Ltd