5470-34-8Relevant academic research and scientific papers
Metal-Free, Rapid, and Highly Chemoselective Reduction of Aromatic Nitro Compounds at Room Temperature
Han, Min Su,Jang, Mingyeong,Lim, Taeho,Park, Byoung Yong
, p. 910 - 919 (2022/01/20)
In this study, we developed a metal-free and highly chemoselective method for the reduction of aromatic nitro compounds. This reduction was performed using tetrahydroxydiboron [B2(OH)4] as the reductant and 4,4′-bipyridine as the organocatalyst and could be completed within 5 min at room temperature. Under optimal conditions, nitroarenes with sensitive functional groups, such as vinyl, ethynyl, carbonyl, and halogen, were converted into the corresponding anilines with excellent selectivity while avoiding the undesirable reduction of the sensitive functional groups.
Enantioselective Synthesis of Azetidines through [3 + 1]-Cycloaddition of Donor-Acceptor Aziridines with Isocyanides
Zhang, Fengcai,Sang, Xinpeng,Zhou, Yuqiao,Cao, Weidi,Feng, Xiaoming
supporting information, p. 1513 - 1517 (2022/03/01)
The enantioselective [3 + 1]-cycloaddition of racemic donor-acceptor (D-A) aziridines with isocyanides was first realized under mild reaction conditions using a chiral N,N′-dioxide/MgIIcomplex as catalyst, providing a facile route to enantioenriched exo-imido azetidines with good to excellent yield (up to 99%) and enantioselectivity (up to 94% ee). An obvious chiral amplification effect was observed in this system, and an explanation was elucidated based on the experimental investigation and X-ray crystal structure of the enantiomerically pure catalyst.
Copper-Catalyzed Cascade N-Dealkylation/N-Methyl Oxidation of Aromatic Amines by Using TEMPO and Oxygen as Oxidants
Li, Dianjun,Wang, Shihaozhi,Yang, Jiale,Yang, Jinhui
supporting information, p. 6768 - 6772 (2021/12/31)
A novel tandem N-dealkylation and N-methyl aerobic oxidation of tertiary aromatic amines to N-arylformamides using copper and TEMPO has been developed. This methodology suggested an alternative synthetic route from N-methylarylamines to N-arylformamides.
HCl-mediated transamidation of unactivated formamides using aromatic amines in aqueous media
Dhawan, Sanjeev,Girase, Pankaj Sanjay,Kumar, Vishal,Karpoormath, Rajshekhar
, p. 3729 - 3739 (2021/10/14)
We report transamidation protocol to synthesize a range of secondary and tertiary amides from weakly nucleophilic aromatic and hetero-aryl amines with low reactive formamide derivatives, utilizing hydrochloric acid as catalyst. This current acid mediated strategy is beneficial because it eliminates the need for a metal catalyst, promoter or additives in the reaction, simplifies isolation and purification. Notably, this approach conventionally used to synthesize molecules on gram scales with excellent yields and a high tolerance for functional groups.
An Environmentally Benign, Catalyst-Free N?C Bond Cleavage/Formation of Primary, Secondary, and Tertiary Unactivated Amides
Kumar, Vishal,Dhawan, Sanjeev,Girase, Pankaj Sanjay,Singh, Parvesh,Karpoormath, Rajshekhar
, p. 5627 - 5639 (2021/11/11)
Herein, we report an operationally simple, cheap, and catalyst-free method for the transamidation of a diverse range of unactivated amides furnishing the desired products in excellent yields. This protocol is environmentally friendly and operates under extremely mild conditions without using any promoter or additives. Significantly, this strategy has been implied in the chemoselective synthesis of a pharmaceutical molecule, paracetamol, on a gram-scale with excellent yield. We anticipate that this universally applicable strategy will be of great interest in drug discovery, biochemistry, and organic synthesis.
Synthesis of aliphatic α-ketoamides from α-substituted methyl ketones: Via a Cu-catalyzed aerobic oxidative amidation
Cha, Hyojin,Chai, Jin Young,Chi, Dae Yoon,Kim, Hyeong Baik
supporting information, p. 4320 - 4326 (2021/05/31)
α-Ketoamides are an important key functional group and have been used as versatile and valuable intermediates and synthons in a variety of functional group transformations. Synthetic methods for making aryl α-ketoamides as drug candidates have been greatly improved through metal-catalyzed aerobic oxidative amidations. However, the preparation of alkyl α-ketoamides through metal-catalyzed aerobic oxidative amidations has not been reported because generating α-ketoamides from aliphatic ketones with two α-carbons theoretically provides two distinct α-ketoamides. Our strategy is to activate the α-carbon by introducing an N-substituent at one of the two α-positions. The key to this strategy is how heterocyclic compounds such as triazoles and imidazoles affect the selectivity of the synthesis of the alkyl α-ketoamides. From this basic concept, and by optimizing the reaction and elucidating the mechanism of the synthesis of aryl α-ketoamides via a copper-catalyzed aerobic oxidative amidation, we prepared fourteen aliphatic α-ketoamides in high yields (48-84%). This journal is
DMF·HCl as a versatile and straightforward N- and O-formylating agent
Ramírez-Vázquez, Dulce G.,Vi?as-Bravo, Omar,Martínez-Pascual, Roxana,Pérez-Picaso, Lemuel,Castro-Cerritos, Karla Viridiana
supporting information, p. 585 - 592 (2020/11/19)
Inspired by the serendipitous isolation of N-formylpiperazines when we attempted the synthesis of a series of piperazines, we have developed a straightforward methodology for the N- and O- formylation of secondary cyclic amines, anilines and steroids, respectively. Such approach is based on the hitherto non-reported use of DMF·HCl complex, as a versatile and easily-available formylating system that can be stored without apparent loss of activity.
Acid-catalyzed chemodivergent reactions of 2,2-dimethoxyacetaldehyde and anilines
Guo, Luxia,Chen, Zihao,Zhu, Hongmei,Li, Minghao,Gu, Yanlong
supporting information, p. 1419 - 1422 (2020/11/12)
Chemodivergent reactions of 2,2-dimethoxyacetaldehyde and anilines were described, which were established on the basis of either a C[sbnd]C bond cleavage or a rearrangement process of a reaction intermediate. These reactions proceeded in a condition-determined manner with good functional group tolerance. In the first model, 2,2-dimethoxyacetaldehyde reacted with aniline to form a new C[sbnd]N bond, in the presence of O2, via a C[sbnd]C bond cleavage reaction. However, in the second model, by performing the reaction in the absence of O2, Heyns rearrangement occurred and generated a new C[sbnd]O bond to form methyl phenylglycinate. Such condition-determined reactions not only offered the new way for value-added conversion of biomass-derived platform molecule, 2, 2-dimethoxyacetaldehyde, but also provided efficient methods for the synthesis of N-arylformamides and methyl phenylglycinates.
Reductive Formylation of Nitroarenes using HCOOH over Bimetallic C?N Framework Derived from the Integration of MOF and COF
Kumar Kar, Ashish,Srivastava, Rajendra
, p. 3174 - 3183 (2021/05/27)
CoZn embedded C?N framework is prepared by the carbonization of CoZn containing MOF integrated with COF porous architecture in Ar atmosphere. The graphitic nature of porous carbon is confirmed from Raman analysis. The porosity and nanostructure information are retrieved from N2-sorption and transmission electron microscopic analysis, respectively. The incorporation of different metals and their oxidation states and types of nitrogen present in the C?N framework are confirmed from X-ray photoelectron spectroscopy. The basicity of the materials is determined from a CO2-temperature programmed desorption. ZnCo embedded C?N framework exhibits excellent activity in the selective reductive formylation using HCOOH. For comparison, more than 15 materials are prepared, and their activities are compared. Several control experiments are performed to establish a structure-activity relation. The recycling experiment, hot-filtration test, and poisoning experiment demonstrate the metal embedded porous C?N framework‘s recyclability and stability. A reaction mechanism for the reductive N-formylation of nitroaromatics is presented based on structure-activity relationship, control reactions, and physicochemical characterizations. The development of interesting MOF-COF-derived metal nanoclusters embedded C?N framework for selective reductive formylation of nitroaromatics using formic acid will be highly attractive to catalysis researchers and industrialists.
