o-Iodoxybenzoic acid (IBX): a versatile reagent for the synthesis of N-substituted pyrroles mediated by β-cyclodextrin in water
摘要:
o-Iodoxybenzoic acid (IBX), a very mild and efficient hypervalent iodine(V) reagent, aromatizes diversely substituted 1-benzylpyrrolidines and N-substituted L-proline analogues to the corresponding substituted pyrroles in good to excellent yields under mild conditions mediated by beta-cyclodextrin in water at room temperature. To the best of our knowledge, this is the first report on IBX, promoting complete aromatization leading to N-benzylpyrroles from the corresponding saturated five membered heterocyclic derivatives in water medium. (C) 2011 Elsevier Ltd. All rights reserved.
GaCl<sub>3</sub>-Catalyzed C–H Cyanation of Indoles with <i>N</i>-Cyanosuccinimide
作者:Xue Wang、Mohamed Makha、Shu-Wei Chen、Huaiji Zheng、Yuehui Li
DOI:10.1021/acs.joc.9b00416
日期:2019.5.17
An efficient GaCl3-catalyzed direct cyanation of indoles and pyrroles using bench-stable electrophilic cyanating agent N-cyanosuccinimide was achieved and afforded 3-cyanoindoles and 2-cyanopyrroles in good yields and excellent regioselectivities. Notably, this protocol exhibited high reactivity for unprotected indoles and was applicable to a broad range of indole and pyrrole substrates.
Sustainable Manganese-Catalyzed Solvent-Free Synthesis of Pyrroles from 1,4-Diols and Primary Amines
作者:Jannik C. Borghs、Yury Lebedev、Magnus Rueping、Osama El-Sepelgy
DOI:10.1021/acs.orglett.8b03506
日期:2019.1.4
A general and selective metal-catalyzed conversion of biomass-derived primary diols and amines to the highly valuable 2,5-unsubstituted pyrroles has been developed. The reaction is catalyzed by a stable nonprecious manganese complex (1 mol %) in the absence of organic solvents whereby water and molecular hydrogen are the only side products. The manganese catalyst shows unprecedented selectivity, avoiding
Palladium‐Catalyzed Regioselective Dehydrogenative C–H/C–H Cross‐Coupling of Pyrroles and Pyridine
<i>N</i>
‐Oxides
作者:Shanshan Liu、C. Christoph Tzschucke
DOI:10.1002/ejoc.201600680
日期:2016.7
The palladium-catalyzed cross-dehydrogenative coupling of N-alkylpyrroles and pyridine N-oxides gave the corresponding pyrrolylpyridine N-oxides. Cu(OAc)2·H2O as a co-catalyst with air as the terminal oxidant led to preferential coupling in the β-position, whereas AgOAc as the stoichiometric oxidant resulted in preferential coupling in the α-position. N-(Benzyloxymethyl)pyrrole derivatives were deprotected
Hypervalent iodine(III): selective and efficient single-electron-transfer (SET) oxidizing agent
作者:Toshifumi Dohi、Motoki Ito、Nobutaka Yamaoka、Koji Morimoto、Hiromichi Fujioka、Yasuyuki Kita
DOI:10.1016/j.tet.2009.10.040
日期:2009.12
ethers, affording the corresponding aromatic cation radicals. Since then, hypervalent iodine(III) has been utilized as a selective and efficient SET oxidizingagent that enables a variety of direct C–H functionalizations of aromatic rings in electron-rich arenes under mild conditions. We have now extended the original method to work in a series of heteroaromatic compounds such as thiophenes, pyrroles,
Friedel−Crafts Acylation of Pyrroles and Indoles using 1,5-Diazabicyclo[4.3.0]non-5-ene (DBN) as a Nucleophilic Catalyst
作者:James E. Taylor、Matthew D. Jones、Jonathan M. J. Williams、Steven D. Bull
DOI:10.1021/ol1025348
日期:2010.12.17
1,5-Diazabicyclo[4.3.0]non-5-ene (DBN) has been shown to be an effective catalyst for the regioselective Friedel−Crafts C-acylation of pyrroles and indoles in high yields. A detailed mechanistic study implies that DBN is acting as a nucleophilic organocatalyst, with the X-ray crystal structure of a key N-acyl-amidine intermediate having been determined for the first time.