N-acylpyrroles were synthesized via olefin ring-closingmetathesis of diallylamines and in situ oxidative aromatization in the presence of the ruthenium Grubbs catalyst and a suitable copper catalyst. In the presence of Cu(OTf)2 and CuBr2, the reaction afforded N-sulfonyl- and N-acylpyrroles, respectively, in one pot. Under an oxygen atmosphere, the reaction went smoothly without the need of hydroperoxide
Synthesis and nuclear magnetic resonance spectroscopic studies of 1-arylpyrroles
作者:Chang Kiu Lee、Jung Ho Jun、Ji Sook Yu
DOI:10.1002/jhet.5570370104
日期:2000.1
A series of m- and p-substituted 1-phenyl, 1-benzyl, 1-benzoyl, and 1-(2-phenylethyl)pyrroles was prepared and their 1H and 13C nmr spectroscopic characteristics were examined. In general, good correlations were observed between the chemical shift values of the βH and the βC of pyrroles [except 1-(2-phenylethyl)pyrroles] and the Hammettt σ. The observation may be explained in terms of the electronic
一系列的米-和p -取代的1-苯基,1-苄基,1-苯甲酰基,和1-(2-苯乙基)吡咯制备和它们的1 H和13 C NMR光谱特性进行了研究。一般情况下,被所述β的化学位移值之间观察到良好的相关性H和β吡咯C [除了1-(2-苯乙基)吡咯]和Hammetttσ。可以用取代基的电子效应来解释该观察结果,所述取代基通过吡咯环的βCs与m-和p之间的p轨道相互作用通过键和空间传输。苯环的Cs。还给出了苯环的1 H和13 C化学位移的1-吡咯基,1-吡咯基甲基和1-吡咯基取代基常数。
Direct oxidative coupling of <i>N</i>-acyl pyrroles with alkenes by ruthenium(<scp>ii</scp>)-catalyzed regioselective C2-alkenylation
C2-alkenylation of N-acyl pyrroles with alkenes has been described. The acyl unit was found to be an effective chelating group for the activation of aryl C-H bonds ortho to the directing group. The alkenylation reaction of benzoyl pyrroles occurred regioselectively at the C2-position of the pyrrole ring, without touching the benzene ring. The reaction provides exclusively monosubstituted pyrroles under the optimized
A Convenient Synthesis of<i>N</i>-Acylpyrroles from Primary Aromatic Amides
作者:Dallas K. Bates、Anil R. Ekkati
DOI:10.1055/s-2003-41020
日期:——
Synthesis of N-acylpyrroles in 45-85% isolated yield from primary aromatic amides and excess 2,5-dimethoxytetrahydrofuran in presence of one equivalent of thionyl chloride is reported. This method has several advantages including short reaction times, mild reaction conditions, and easy workup. The technique works particularly well for deactivated aromatic amides.
C2-arylation of N-acyl pyrroles with arylhalides is developed for the first time using Pd(PPh3)4 as a catalyst in combination with Ag2CO3 under air, which allowed the application of a good compatibility catalytic system. This protocol provides a straightforward method for the preparation of valuable arylated pyrroles in moderate to good yields under the standard conditions with good substrate tolerance
N-酰基吡咯与芳基卤化物的C2-芳基化反应是首次使用Pd(PPh 3)4作为催化剂与Ag 2 CO 3组合在空气中进行的,这使得可应用良好相容性的催化体系。该方案提供了一种简单的方法,可在标准条件下以良好的底物耐受性以中等至良好的产率制备有价值的芳基化吡咯。有趣的是,尽管N-苯甲酰基吡咯反应良好,但使用具有噻吩或呋喃环的底物表明,对于本催化体系,噻吩和呋喃环比吡咯更具反应性。