5044-32-6Relevant academic research and scientific papers
Direct oxidative coupling of: N -acyl pyrroles with alkenes by ruthenium(ii)-catalyzed regioselective C2-alkenylation
Chen, Weiqiang,Li, Hui-Jing,Li, Qin-Ying,Wu, Yan-Chao
supporting information, p. 500 - 513 (2020/01/30)
Ruthenium(ii)-catalyzed oxidative coupling by 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 conditions. Disubstituted pyrroles could be obtained using higher loadings of the ruthenium(ii)-catalyst and the additives.
Ni-Catalyzed cross-coupling reactions of N-acylpyrrole-type amides with organoboron reagents
Huang, Pei-Qiang,Chen, Hang
, p. 12584 - 12587 (2017/11/30)
The catalytic conversion of amides to ketones is highly desirable yet challenging in organic synthesis. We herein report the first Ni/bis-NHC-catalyzed cross-coupling of N-acylpyrrole-type amides with arylboronic esters to obtain diarylketones. This method is facilitated by a new chelating bis-NHC ligand. The reaction tolerates diverse functional groups on both arylamide and arylboronic ester partners including sensitive ester and ketone groups.
Suzuki-Miyaura Cross-Coupling of N-Acylpyrroles and Pyrazoles: Planar, Electronically Activated Amides in Catalytic N-C Cleavage
Meng, Guangrong,Szostak, Roman,Szostak, Michal
, p. 3596 - 3599 (2017/07/15)
The formation of C-C bonds from amides by catalytic activation of the amide bond has been thus far possible by steric distortion. Herein, we report the first example of a general Pd-catalyzed Suzuki-Miyaura cross-coupling of planar amides enabled by the combination of (i) electronic-activation of the amide nitrogen in N-acylpyrroles and pyrazoles and (ii) the use of a versatile Pd-NHC catalysis platform. The origin and selectivity of forming acylmetals, including the role of twist, are discussed.
Palladium-catalyzed Suzuki-Miyaura coupling of amides by carbon-nitrogen cleavage: General strategy for amide N-C bond activation
Meng, Guangrong,Szostak, Michal
supporting information, p. 5690 - 5707 (2016/07/06)
The first palladium-catalyzed Suzuki-Miyaura cross-coupling of amides with boronic acids for the synthesis of ketones by sterically-controlled N-C bond activation is reported. The transformation is characterized by operational simplicity using bench-stable, commercial reagents and catalysts, and a broad substrate scope, including substrates with electron-donating and withdrawing groups on both coupling partners, steric-hindrance, heterocycles, halides, esters and ketones. The scope and limitations are presented in the synthesis of >60 functionalized ketones. Mechanistic studies provide insight into the catalytic cycle of the cross-coupling, including the first experimental evidence for Pd insertion into the amide N-C bond. The synthetic utility is showcased by a gram-scale cross-coupling and cross-coupling at room temperature. Most importantly, this process provides a blueprint for the development of a plethora of metal catalyzed reactions of typically inert amide bonds via acyl-metal intermediates. A unified strategy for amide bond activation to enable metal insertion into N-C amide bond is outlined (Scheme 1).
Polystyrene-supported GaCl3 as a highly efficient and recyclable heterogeneous Lewis acid catalyst for one-pot synthesis of N-substituted pyrroles
Rahmatpour, Ali
experimental part, p. 15 - 19 (2012/07/03)
A new and environmentally benign method for the preparation of N-substituted pyrroles from one-pot condensation reaction of 2,5-hexanedione with amines and diamines in the presence of polystyrene-supported gallium trichloride (PS/GaCl3) as a highly active and reusable heterogeneous Lewis acid catalyst is presented. This new protocol has the advantages of easy availability, stability, reusability and eco-friendly of the catalyst, high to excellent yields, simple experimental and work-up procedure.
ZrOCl2·8H2O as a highly efficient, eco-friendly and recyclable Lewis acid catalyst for one-pot synthesis of N-substituted pyrroles under solvent-free conditions at room temperature
Rahmatpour, Ali
experimental part, p. 585 - 590 (2011/10/18)
A new and efficient method for the synthesis of a variety of N-substituted pyrroles from condensation reactions of 2,5-hexanedione with amines or diamines using ZrOCl2·8H2O as a water-tolerant Lewis acid catalyst at room temperature is described.The use of nontoxic, inexpensive, easily available and reusable catalyst under solvent-free conditions make this protocol practical, environmentally friendly and economically attractive.
Oxidation of 2,5-dialkylpyrrole derivatives with cerium(IV) ammonium nitrate
Voloshchuk, Roman,Galezowski, Michal,Gryko, Daniel T.
experimental part, p. 1147 - 1152 (2009/12/04)
A new four-step procedure for the synthesis of 2,5-diformylpyrrole from hexane-2,5-dione was developed. The oxidation reaction of substituted 2,5-dialkylpyrroles with cerium(IV) ammonium nitrate (CAN) has been studied in detail. It was found that the outc
A General Synthesis of Pyrroles from Aldehydes and Ketones
Baldwin, Jack E.,Bottaro, Jeffrey C.
, p. 624 - 625 (2007/10/02)
The azines of enolisable aldehydes and ketones are converted into pyrroles via thermal rearrangement of the derived benzoyl derivatives and subsequent hydrazinolysis of the resulting N-benzoylpyrroles.
