The selective oxidation of C2-alkyl-substituted indoles to 3-oxindole and the selective C–H oxygenation or amination of C2,C3-dialkyl-substituted indoles at C2 are reported under mild conditions. The position of the alkyl substitution on the indole directs the reaction to different pathways under similar conditions.
One-pot, three-component Fischer indolisation–<i>N</i>-alkylation for rapid synthesis of 1,2,3-trisubstituted indoles
作者:Christopher A. Hughes-Whiffing、Alexis Perry
DOI:10.1039/d0ob02185g
日期:——
A one-pot, three-component protocol for the synthesis of 1,2,3-trisubstituted indoles has been developed, based upon a Fischer indolisation–indole N-alkylation sequence. This procedure is very rapid (total reaction time under 30 minutes), operationally straightforward, generally high yielding and draws upon readily available building blocks (aryl hydrazines, ketones, alkyl halides) to generate densely
Frustrated Lewis Pair Catalyzed Dehydrogenative Oxidation of Indolines and Other Heterocycles
作者:Alexander F. G. Maier、Sebastian Tussing、Tobias Schneider、Ulrich Flörke、Zheng-Wang Qu、Stefan Grimme、Jan Paradies
DOI:10.1002/anie.201606426
日期:2016.9.26
An acceptorless dehydrogenation of heterocyclescatalyzed by frustrated Lewis pairs (FLPs) was developed. Oxidation with concomitant liberation of molecular hydrogen proceeded in high to excellent yields for N‐protected indolines as well as four other substrate classes. The mechanism of this unprecedented FLP‐catalyzed reaction was investigated by mechanistic studies, characterization of reaction intermediates
diastereo- and enantioselective BOX/Cu(II)-catalyzed C2,C3-cyclopentannulation of indoles with donor-acceptor cyclopropanes has been developed on the basis of asymmetric formal [3 + 2] cycloaddition of indoles. This reaction provides rapid and facile access to a series of enantioenriched cyclopenta-fused indoline products and can be further extended to the construction of tetracyclic pyrroloindolines. The synthetic
Iodine-Catalyzed C–H Amidation and Imination at the 2α-Position of 2,3-Disubstituted Indoles with Chloramine Salts
作者:Xiaozu Liu、Yuxiang Zhou、Zhongqin Yang、Qin Li、Liang Zhao、Peijun Liu
DOI:10.1021/acs.joc.8b00286
日期:2018.4.20
A novel iodine-catalyzed amidation and imination at the 2α-position of 2,3-disubstituted indoles in the presence of chloramine salts with high regioselectivity has been achieved. The protocol is applicable to a wide range of substrates to deliver the corresponding 2α-nitrogen-containing indole derivatives. Furthermore, to demonstrate the synthetic value of this established transformation, a concise