Regioselective Synthesis of Indoles
<i>via</i>
Rhodium‐Catalyzed CH Activation Directed by an
<i>In‐Situ</i>
Generated Redox‐Neutral Group
作者:Krishnamoorthy Muralirajan、Chien‐Hong Cheng
DOI:10.1002/adsc.201400224
日期:2014.5.5
A regioselective synthesis of indoles from arylhydrazine hydrochlorides with alkynes and diethyl ketone catalyzed by a rhodium complex is described. A possible mechanism involving an in‐situ generated oxidizing directing group NNCR1R2 assisted ortho‐CHactivation and reductive elimination are proposed. The catalytic reaction is highly compatible with a wide range of functional arylhydrazines and
Indole Synthesis by Rhodium(III)-Catalyzed Hydrazine-Directed CH Activation: Redox-Neutral and Traceless by NN Bond Cleavage
作者:Dongbing Zhao、Zhuangzhi Shi、Frank Glorius
DOI:10.1002/anie.201306098
日期:2013.11.18
Fishing for complements! There is an alternative to the useful Fischer indole synthesis. The new method utilizes the same retrosynthetic disconnection but is based on a RhIII‐catalyzed directed CH activation step and a successive coupling with alkynes.
Novel and Efficient Heterogeneous 4-Methylbenzenesulfonic Acid-Based Ionic Liquid Supported on Silica Gel for Greener Fischer Indole Synthesis
作者:Yu-Lin Hu、Dong Fang、Dong-Sheng Li
DOI:10.1007/s10562-016-1721-x
日期:2016.5
gel (IL-SO3H-SiO2) has been prepared, and characterized by FT-IR, XRD, TGA, SEM and EDX spectra. Then, IL-SO3H-SiO2 was utilized as an efficient and heterogeneous catalyst for the synthesis of indoles via the one-pot Fischer reaction of phenyl hydrazines with ketones or aldehydes at room temperature. The heterogeneous catalyst could be recovered easily by filtration and reused many times without significant
A redox‐neutral cobalt(III)‐catalyzed synthetic approach for the direct synthesis of unprotected indoles showcasing an N−Nbondcleavage is reported. The herein newly introduced Boc‐protected hydrazines establish a beneficial addition to the limited portfolio of oxidizing directing groups for cobalt(III) catalysis. Moreover, the developed catalytic methodology tolerates a good variety of functional
One-pot oxidative hydrolysis-oxidative cleavage of 7-borylindoles enables access to <i>o</i>-amidophenols and 4-acylbenzoxazoles
作者:Kirsty Anderson、Andrew S. Eastabrook、Jonathan Sperry
DOI:10.1039/c9cc09807k
日期:——
o-amidophenol derivatives. Subsequent cyclisation delivers benzoxazoles bearing an acyl group at C4, a substitution pattern common to fungal-derived benzoxazole alkaloids. Using 7-borylindoles as substrates to access functionalised o-amidophenols circumvents the difficult preparation of these compounds from arenes, streamlining access to substituted 4-acylbenzoxazoles in the process.