5422-63-9Relevant academic research and scientific papers
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.
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.
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.
Borane-Trimethylamine Complex as a Reducing Agent for Selective Methylation and Formylation of Amines with CO2
Zhang, Yanmeng,Zhang, He,Gao, Ke
supporting information, p. 8282 - 8286 (2021/10/25)
We report herein that a borane-trimethylamine complex worked as an efficient reducing agent for the selective methylation and formylation of amines with 1 atm CO2 under metal-free conditions. 6-Amino-2-picoline serves as a highly efficient catalyst for the methylation of various secondary amines, whereas in its absence, the formylation of primary and secondary amines was achieved in high yield with high chemoselectivity. Mechanistic studies suggest that the 6-amino-2-picoline-borane catalytic system operates like an intramolecular frustrated Lewis pair to activate CO2.
Tetracoordinate borates as catalysts for reductive formylation of amines with carbon dioxide
Du, Chen-Xia,Huang, Zijun,Jiang, Xiaolin,Li, Yuehui,Makha, Mohamed,Wang, Fang,Zhao, Dongmei
supporting information, p. 5317 - 5324 (2020/09/17)
We report sodium trihydroxyaryl borates as the first robust tetracoordinate organoboron catalysts for reductive functionalization of CO2. These catalysts, easily synthesized from condensing boronic acids with metal hydroxides, activate main group element-hydrogen (E-H) bonds efficiently. In contrast to BX3 type boranes, boronic acids and metal-BAr4 salts, under transition metal-free conditions, sodium trihydroxyaryl borates exhibit high reactivity of reductive N-formylation toward a variety of amines (106 examples), including those with functional groups such as ester, olefin, hydroxyl, cyano, nitro, halogen, MeS-, ether groups, etc. The over-performance to catalyze formylation of challenging pyridyl amines affords a promising alternative method to the use of traditional formylation reagents. Mechanistic investigation supports electrostatic interactions as the key for Si/B-H activation, enabling alkali metal borates as versatile catalysts for hydroborylation, hydrosilylation, and reductive formylation/methylation of CO2.
Selective Gold-Catalysed Synthesis of Cyanamides and 1-Substituted 1H-Tetrazol-5-Amines from Isocyanides
?koch, Karel,Císa?ová, Ivana,?těpni?ka, Petr
supporting information, p. 13788 - 13791 (2018/09/14)
The newly discovered gold-catalysed reaction of isocyanides with hydrazoic acid generated in situ from trimethylsilyl azide and methanol (or, alternatively, from NaN3/AcOH) produces either cyanamides or 1-substituted 1H-tetrazol-5-amines, depending on the amount of available HN3. The reaction proceeds selectively and in generally high yields of either product, thus providing a particularly convenient access to a wide range of substituted 1H-tetrazol-5-amines that are rather difficult to access otherwise.
TEMPO-Catalyzed Aerobic Oxidative Selenium Insertion Reaction: Synthesis of 3-Selenylindole Derivatives by Multicomponent Reaction of Isocyanides, Selenium Powder, Amines, and Indoles under Transition-Metal-Free Conditions
Liu, Huan,Fang, Yi,Wang, Shun-Yi,Ji, Shun-Jun
supporting information, p. 930 - 933 (2018/02/22)
A novel and efficient approach for the selenium functionalization of indoles was developed with selenium powder as the selenium source, catalyzed by 2,2,6,6-tetramethylpiperidinooxy (TEMPO) and employing O2 as the green oxidant. This protocol provides a practical route for the synthesis of 3-selenylindole derivatives and has the advantages of readily available starting materials, mild reaction conditions, and a wide scope of substrates. Electron spin-resonance (ESR) studies reveal that the approach involves the formation of nitrogen-centered radicals and selenium radicals via oxidation of in situ generated selenoates.
Diverse catalytic reactivity of a dearomatized PN3P?-nickel hydride pincer complex towards CO2 reduction
Li, Huaifeng,Gon?alves, Théo P.,Zhao, Qianyi,Gong, Dirong,Lai, Zhiping,Wang, Zhixiang,Zheng, Junrong,Huang, Kuo-Wei
supporting information, p. 11395 - 11398 (2018/10/20)
A dearomatized PN3P?-nickel hydride complex has been prepared using an oxidative addition process. The first nickel-catalyzed hydrosilylation of CO2 to methanol has been achieved, with unprecedented turnover numbers. Selective methylation and formylation of amines with CO2 were demonstrated by such a PN3P?-nickel hydride complex, highlighting its versatile functions in CO2 reduction.
[Ph3C][B(C6F5)4]: A Highly Efficient Metal-Free Single-Component Initiator for the Helical-Sense-Selective Cationic Copolymerization of Chiral Aryl Isocyanides and Achiral Aryl Isocyanides
Yan, Xinwen,Zhang, Shaowen,Zhang, Pengfei,Wu, Xiaolu,Liu, An,Guo, Ge,Dong, Yuping,Li, Xiaofang
, p. 8947 - 8952 (2018/07/25)
Commercially available [Ph3C][B(C6F5)4] served as a highly efficient metal-free and single-component initiator not only for the carbocationic polymerization of polar and bulky aryl isocyanides with extremely high activity up to 1.2×107 g of polymer/(molcat. h), but also for the helical-sense-selective polymerization of chiral aryl isocyanides and copolymerization with achiral aryl isocyanides to afford high-molecular-weight functional poly(aryl isocyanide)s with good solubility as well as AIE characteristics and/or a single-handed helical conformation.
Electrochemical N -Formylation of Amines via Decarboxylation of Glyoxylic Acid
Lin, Dian-Zhao,Huang, Jing-Mei
supporting information, p. 2112 - 2115 (2018/04/14)
A new method for the synthesis of formamides has been developed through electrochemical decarboxylative N-formylation of amines with glyoxylic acid. This protocol provides an efficient approach to formamides with a broad range of functional group tolerance under ambient conditions.
