85909-02-0Relevant articles and documents
Synthesis of Sulfoxonium Ylides from Amides by Selective N-C(O) Activation
Rahman, Md. Mahbubur,Szostak, Michal
supporting information, p. 4818 - 4822 (2021/06/28)
The direct synthesis of sulfoxonium ylides from amides by selective N-C(O) cleavage is presented. The reaction proceeds through the nucleophilic addition of dimethylsulfoxonium methylide to the amide bond in acyclic twisted amides under exceedingly mild r
Ball-milling enables highly selective solvent-free N-tert-butoxycarbonylation for activation of amides
Shi, Weijia,Sun, Guoping,Zou, Gang
supporting information, (2020/07/03)
A ball-milling enabled chemoselective activation of amides via N-tert-butoxycarbonylation catalyzed by 4-dimethylaminopyridine is described under solvent-free conditions. High chemoselectivity with respect to NH acidity of amides has been observed. A one-pot two-step procedure for selective esterification of amides has been demonstrated in model reaction of benzamides with p-cresol and benzyl alcohol.
N-Heterocyclic Carbene/Cobalt Cooperative Catalysis for the Chemo- and Regioselective C?N Bond Formation between Aldehyde and Amines/Amides
Siddiqui, Asher M.,Khalid, Anam,Khan, Arif,Azad, Chandra S.,Samim, Mohd.,Khan, Imran A.
, p. 4281 - 4287 (2020/07/24)
A novel methodology for the construction of various secondary (4 examples), tertiary amides (31 examples), and imides (16 examples) by a Cobalt(II) catalyzed oxidative amide coupling in aqueous media. The Co(III)-TMC was reacted with N-Heteroatom Carbene to form active catalyst Co(II)NHC-TMC in situ which involves in the coordination with Breslow's intermediate and SET for the activation of aldehyde and amides. The mechanism for activation of amide and amine differs on the basis of SET based nucleophilic addition and ligand exchange respectively. The regeneration of the catalyst was achieved using Fe(III)(EDTA)-H2O2 as oxidant. The use of Co(II)TMC-O2 was also found equally efficient in the process. The method is found regioselective for N?H activation in the presence of equally susceptible ortho-C?H bond activation. And amines were found more susceptible then the corresponding amide for the reaction.
Water Phase, Room Temperature, Ligand-Free Suzuki–Miyaura Cross-Coupling: A Green Gateway to Aryl Ketones by C–N Bond Cleavage
Zhang, Yuqi,Wang, Zijia,Tang, Zhao,Luo, Zhongfeng,Wu, Hongxiang,Liu, Tingting,Zhu, Yulin,Zeng, Zhuo
, p. 1620 - 1628 (2020/03/04)
We report herein a green strategy for synthesis of aryl ketones from twisted amides by using Pd(OAc)2 as catalysts. This method shows high functional group tolerance to offer a variety of ketones in good yields under mild conditions (up to 94 %). Notably, this methodology demonstrates the first water phase, room temperature, ligand-free Suzuki–Miyaura coupling through C–N bond cleavage, which is environmentally friendly and might facilitate the development of amide based green chemistry.
Metal-Free Transamidation of Secondary Amides by N-C Cleavage
Rahman, Md. Mahbubur,Li, Guangchen,Szostak, Michal
, p. 12091 - 12100 (2019/10/11)
Transamidation reactions represent a fundamental chemical process involving conversion of one amide functional group into another. Herein, we report a facile, highly chemoselective method for transamidation of N-tert-butoxycarbonylation (N-Boc) activated secondary amides that proceeds under exceedingly mild conditions in the absence of any additives. Because this reaction is performed in the absence of metals, oxidants, or reductants, the reaction tolerates a large number of useful functionalities. The reaction is compatible with diverse amides and nucleophilic amines, affording the transamidation products in excellent yields through direct nucleophilic addition to the amide bond. The utility of this methodology is highlighted in the synthesis of Tigan, a commercial antiemetic, directly from the amide bond. We expect that this new metal-free transamidation will have broad implications for the development of new transformations involving direct nucleophilic addition to the amide bond as a key step.
Catalyst-Free, Metal-Free, and Chemoselective Transamidation of Activated Secondary Amides
Ramkumar, Rajagopal,Chandrasekaran, Srinivasan
, p. 921 - 932 (2019/02/10)
A simple protocol, which is catalyst-free, metal-free, and chemoselective, for transamidation of activated secondary amides in ethanol as solvent under mild conditions is reported. A wide range of amines, amino acids, amino alcohols, and the substituents, which are problematic in catalyzed transamidation, are tolerated in this methodology. The transamidation reaction was successfully extended to water as the medium as well. The present methodology appears to be better than the other catalyzed transamidations reported recently.
Na2CO3-promoted thioesterification via N–C bond cleavage of amides to construct thioester derivatives
Tao, Jiasi,Yu, Weijie,Luo, Jin,Wang, Tao,Ge, Wanling,Zhang, Ziwei,Yang, Bingjie,Xiong, Fei
, p. 486 - 492 (2019/11/03)
A mild, efficient, and transition-metal-free catalytic strategy is developed to construct thioesters via selective N–C bond cleavage of Boc2-activated primary amides. This strategy is successfully carried out with stoichiometric Na2C
Chemoselective Synthesis of Aryl Ketones from Amides and Grignard Reagents via C(O)-N Bond Cleavage under Catalyst-Free Conditions
Sureshbabu, Popuri,Azeez, Sadaf,Muniyappan, Nalluchamy,Sabiah, Shahulhameed,Kandasamy, Jeyakumar
, p. 11823 - 11838 (2019/10/02)
Conversion of a wide range of N-Boc amides to aryl ketones was achieved with Grignard reagents via chemoselective C(O)-N bond cleavage. The reactions proceeded under catalyst-free conditions with different aryl, alkyl, and alkynyl Grignard reagents. α-Ketoamide was successfully converted to aryl diketones, while α,β-unsaturated amide underwent 1,4-addition followed by C(O)-N bond cleavage to provide diaryl propiophenones. N-Boc amides displayed higher reactivity than Weinreb amides with Grignard reagents. A broad substrate scope, excellent yields, and quick conversion are important features of this methodology.
Palladium-Catalyzed Aerobic Oxidative Coupling of Amides with Arylboronic Acids by Cooperative Catalysis
Li, Yue,Wu, Hongxiang,Zeng, Zhuo
supporting information, p. 4357 - 4361 (2019/07/09)
The first fluoride and palladium co-catalyzed conversion of amide to ester through an aerobic oxidative coupling pathway is reported. This new approach presents a practical process that employs easily available oxygen and commercially available arylboronic acids as coupling partners, uses a wide range of N- tosylamides, and proceeds under mild reaction conditions. This protocol demonstrates broad functional group tolerance, and provides an alternative option to synthesize esters from N-tosylamides which obtained by simply N-functionalization of secondary amides.
Fluoride-Catalyzed Esterification of Amides
Wu, Hongxiang,Guo, Weijie,Daniel, Stelck,Li, Yue,Liu, Chao,Zeng, Zhuo
supporting information, p. 3444 - 3447 (2018/02/21)
In recent years, it has been demonstrated that amide carbon–nitrogen bonds can be activated and selectively cleaved using transition metal catalysts. However, these methodologies have been restricted to specific amides; a one-to-one relationship exists between the catalytic system and the amides and also uses large amounts of transition-metal catalysts and ligands. Hence, we now report a general strategy for esterification of common amides using fluoride as a catalyst. This method shows high functional group tolerance, and notably it requires only a slight excess of the alcohol nucleophile, which is a rare case in transition-metal-free amide transformations. Moreover, this approach may provide a new understanding for further studies on esterification of amides and is expected to stimulate the development of alternative methods for direct functionalization of amides.
