5145-65-3Relevant academic research and scientific papers
Pd-Catalyzed Double-Decarbonylative Aryl Sulfide Synthesis through Aryl Exchange between Amides and Thioesters
Bie, Fusheng,Cao, Han,Liu, Chengwei,Liu, Xuejing,Shi, Yijun,Szostak, Michal,Zhou, Tongliang
supporting information, p. 8098 - 8103 (2021/10/25)
We report the palladium-catalyzed double-decarbonylative synthesis of aryl thioethers by an aryl exchange reaction between amides and thioesters. In this method, amides serve as aryl donors and thioesters are sulfide donors, enabling the synthesis of valuable aryl sulfides. The use of Pd/Xantphos without any additives has been identified as the catalytic system promoting the aryl exchange by C(O)-N/C(O)-S cleavages. The method is amenable to a wide variety of amides and sulfides.
A Fast and General Route to Ketones from Amides and Organolithium Compounds under Aerobic Conditions: Synthetic and Mechanistic Aspects
Ghinato, Simone,Territo, Davide,Maranzana, Andrea,Capriati, Vito,Blangetti, Marco,Prandi, Cristina
supporting information, p. 2868 - 2874 (2021/01/21)
We report that the nucleophilic acyl substitution reaction of aliphatic and (hetero)aromatic amides by organolithium reagents proceeds quickly (20 s reaction time), efficiently, and chemoselectively with a broad substrate scope in the environmentally responsible cyclopentyl methyl ether, at ambient temperature and under air, to provide ketones in up to 93 % yield with an effective suppression of the notorious over-addition reaction. Detailed DFT calculations and NMR investigations support the experimental results. The described methodology was proven to be amenable to scale-up and recyclability protocols. Contrasting classical procedures carried out under inert atmospheres, this work lays the foundation for a profound paradigm shift of the reactivity of carboxylic acid amides with organolithiums, with ketones being straightforwardly obtained by simply combining the reagents under aerobic conditions and with no need of using previously modified or pre-activated amides, as recommended.
Direct C2-arylation ofN-acyl pyrroles with aryl halides under palladium catalysis
Chen, Weiqiang,Li, Hui-Jing,Cheng, Yun-Fei,Wu, Yan-Chao
supporting information, p. 1555 - 1564 (2021/03/01)
C2-arylation ofN-acyl pyrroles with aryl halides is developed for the first time using Pd(PPh3)4as a catalyst in combination with Ag2CO3under 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. Interestingly, whileN-benzoyl pyrroles reacted well, the use of substrates with a thiophene or furan ring indicated that the thiophene and furan rings are more reactive than pyrrole for the present catalytic system.
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.
Dinuclear manganese alkoxide complexes as catalysts for C-N bond cleavage of simple tertiary: N, N -dialkylamides to give esters
Nagae, Haruki,Hirai, Takahiro,Kato, Daiki,Soma, Shusei,Akebi, Shin-Ya,Mashima, Kazushi
, p. 2860 - 2868 (2019/03/13)
Amide bonds are stable due to the resonance between the nitrogen lone pair and the carbonyl moiety, and therefore the chemical transformation of amides, especially tertiary amides, involving C-N bond fission is considered one of the most difficult organic reactions, unavoidably requiring harsh reaction conditions and strong acids or bases. We report the catalytic C-N bond cleavage of simple tertiary N,N-dialkylamides to give corresponding esters using a catalyst system (2 mol% based on Mn atoms) of a tetranuclear manganese alkoxide, [Mn(acac)(OEt)(EtOH)]4 (1c), combined with four equivalents of 4,7-bis(dimethylamino)-1,10-phenanthroline (L1: Me2N-Phen). Regarding the reaction mechanism, we isolated a dinuclear manganese complex, [Mn(acac)(OEt)(Phen)]2 (6c), which was revealed as the catalytically active species for the esterification of tertiary amides.
Synthesis of N -Sulfonyl- and N -Acylpyrroles via a Ring-Closing Metathesis/Dehydrogenation Tandem Reaction
Chen, Weiqiang,Li, Hui-Jing,Liu, Ying,Nan, Xiang,Wu, Yan-Chao,Zhang, Yin-Lin
, p. 3651 - 3666 (2019/09/30)
N -Sulfonyl- and N -acylpyrroles were synthesized via olefin ring-closing metathesis 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/s
Suzuki-Miyaura Cross-Coupling of N-Acylpyrroles and Pyrazoles: Planar, Electronically Activated Amides in Catalytic N-C Cleavage
Meng, Guangrong,Szostak, Roman,Szostak, Michal
supporting information, 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.
Ni-Catalyzed cross-coupling reactions of N-acylpyrrole-type amides with organoboron reagents
Huang, Pei-Qiang,Chen, Hang
supporting information, 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.
Reactivity of 7-Azanorbornenes in Bioorthogonal Inverse Electron-Demand Diels–Alder Reactions
Karaki, Fumika,Ohgane, Kenji,Imai, Hirotaka,Itoh, Kennosuke,Fujii, Hideaki
, p. 3815 - 3829 (2017/07/22)
In the preparation of multicomponent compounds, the accumulation of components through sequential click reactions is an attractive strategy. In this work we examined the reactivity of various N-substituted 7-azanorbornenes in inverse electron-demand Diels–Alder (iEDDA) reactions with tetrazines to explore the potential of 7-azanorbornenes as clickable hub molecules. The iEDDA reaction of 7-azanorbornene is expected to proceed faster when the nitrogen atom at the 7-position is substituted with an electron-donating substituent. Contrary to this expectation, the electron-donating alkyl-bearing derivative reacted much more slowly than those bearing electron-withdrawing acyl groups. The results of DFT calculations indicate that the reaction rates correlate well with an increase in sp2 character of the 7-nitrogen atoms: The ease of conversion of the more stable exo conformer into the more reactive endo conformer may lower the activation energy of the first rate-determining hetero-Diels–Alder step. Indeed, the reaction rates of N-acylated 7-azanorbornenes, which have a more planar nitrogen atom, were found superior to those of other derivatives and comparable to those of norbornenes. Finally, we successfully labeled a tetrazine on a protein surface by fluorophore-conjugated 7-azanorbornene in the presence of other proteins.
Samarium-mediated intramolecular cross-couplings of an α,β-unsaturated N-acylpyrrole
Law, Katherine R.,McErlean, Christopher S.P.
supporting information, p. 3113 - 3116 (2016/07/06)
The first example of an α,β-unsaturated N-acylpyrrole undergoing a SmI2-mediated cyclization is reported. In contrast to other unsaturated units, the intermediate samarium enolate readily engages in aldol-type reactions, necessitating careful control of the reaction conditions.
