1129-50-6Relevant academic research and scientific papers
The catalytic activity of titania nanostructures in the synthesis of amides under solvent-free conditions
Nagarajan, Sangaraiah,Ran, Park,Shanmugavelan, Poovan,Sathishkumar, Murugan,Ponnuswamy, Alagusundaram,Suk Nahm, Kee,Gnana Kumar
, p. 1312 - 1319 (2012)
Different shapes and phases of titania nanostructures with the uniform size distribution were synthesized by hydrothermal sol-gel technique. The influence of annealing temperature on the crystalline character, size and phase of the prepared nanomaterials were evidenced from the diffraction analysis. Infrared spectroscopic analysis ensured the structural confirmation of the sulfated titania nanostructures. Catalytic activity of the synthesized nanometric materials in direct amidation of aromatic and aliphatic carboxylic acids with aromatic amines was evaluated. Among the materials studied, sulfated titania nanotubes with the anatase phase exhibited excellent catalytic activity. The employed solvent-free protocol is greener and eradicates the drawbacks associated with the hazardous solvents employed in the prevailing solution phase methodologies.
Enzymes in organic synthesis - VII: Enzymatic acylation of amines
Djeghaba,Deleuze,De Jeso,Messadi,Maillard
, p. 761 - 762 (1991)
Lipases and esterases catalyze amide synthesis from primary amines in the presence of various esters. Lipase SP 382 exhibited a very high activity and specificity.
An efficient synthesis of amides from alcohols and azides catalyzed by a bifunctional catalyst Au/DNA under mild conditions
Guo, Xuefeng,Tang, Lin,Yang, Yu,Zha, Zhenggen,Wang, Zhiyong
, p. 2443 - 2447 (2014)
A novel Au/DNA-catalyzed amidation from alcohols and azides was developed under mild conditions. Taking advantage of the water-soluble reversibility of this catalyst, the transformation could be carried out smoothly in water and the catalyst could be recovered and reused by a simple phase separation. This amidation reaction unitized the hydrogen transfer process and the oxidative coupling process synergistically in an atom economical and environmentally benign synthesis. the Partner Organisations 2014.
Visible-Light Carbon Nitride-Catalyzed Aerobic Cyclization of Thiobenzanilides under Ambient Air Conditions
Bai, Jin,Yan, Sijia,Zhang, Zhuxia,Guo, Zhen,Zhou, Cong-Ying
supporting information, p. 4843 - 4848 (2021/06/28)
A metal-free heterogeneous photocatalysis has been developed for the synthesis of benzothiazoles via intramolecular C-H functionalization/C-S bond formation of thiobenzanilides by inexpensive graphitic carbon nitride (g-C3N4) under visible-light irradiation. This reaction provides access to a broad range of 2-substituted benzothiazoles in high yields under an air atmosphere at room temperature without addition of a strong base or organic oxidizing reagents. In addition, the catalyst was found to be stable and reusable after five reaction cycles.
Visible-light induced one-pot hydrogenation and amidation of nitroaromatics with carboxylic acids over 2D MXene-derived Pt/N-TiO2/Ti3C2
Jiang, Heyan,Hu, Zujie,Gan, Chuan,Sun, Bin,Kong, Shuzhen,Bian, Fengxia
, (2021/03/03)
Pt nanoparticles supported on N doped titanium dioxide/titanium carbide (MXene) heterojunctions were employed as photocatalysts for the tandem reactions between aromatic nitro compounds and carboxylic acids to produce amide products. The 3%Pt/N-TiO2/Ti3C2 heterojunction was prepared by in situ grew TiO2 on Ti3C2 nanosheets and then N doped TiO2 with melamine, Pt nanoparticles with 3.3 nm mean diameter well dispersed on N-TiO2/Ti3C2. 3%Pt/N-TiO2/Ti3C2 had excellent amidation activity and chemoselectivity under visible-light irradiation. The elevated catalytic performance of 3%Pt/N-TiO2/Ti3C2 was owing to the improvement in photogenerated electron and hole separation efficiency through charge short-range directional transmission caused by the intimate contact between the TiO2 and the conductive Ti3C2. This direct hydrogenation along with amidation between nitroaromatics and carboxylic acids own actual merits in the amides produce with no harmful byproducts. In situ DRIFTS spectra verified that the amidation activation with visible light irradiation at 25 °C was much faster than heating.
Photocatalyzed Triplet Sensitization of Oximes Using Visible Light Provides a Route to Nonclassical Beckmann Rearrangement Products
Zhang, Xiao,Rovis, Tomislav
, p. 21211 - 21217 (2021/12/27)
Oximes are valuable synthetic intermediates for the preparation of a variety of functional groups. To date, the stereoselective synthesis of oximes remains a major challenge, as most current synthetic methods either provide mixtures of E and Z isomers or furnish the thermodynamically preferred E isomer. Herein we report a mild and general method to achieve Z isomers of aryl oximes by photoisomerization of oximes via visible-light-mediated energy transfer (EnT) catalysis. Facile access to (Z)-oximes provides opportunities to achieve regio- and chemoselectivity complementary to those of widely used transformations employing oxime starting materials. We show an enhanced one-pot protocol for photocatalyzed oxime isomerization and subsequent Beckmann rearrangement that enables novel reactivity with alkyl groups migrating preferentially over aryl groups, reversing the regioselectivity of the traditional Beckmann reaction. Chemodivergent N- or O- cyclizations of alkenyl oximes are also demonstrated, leading to nitrones or cyclic oxime ethers, respectively.
Cobalt-Catalyzed Deoxygenative Hydroboration of Nitro Compounds and Applications to One-Pot Synthesis of Aldimines and Amides
Gudun, Kristina A.,Hayrapetyan, Davit,Khalimon, Andrey Y.,Segizbayev, Medet,Slamova, Ainur,Zakarina, Raikhan
, (2021/11/30)
The commercially available and bench-stable Co(acac)2 ligated with bis[(2-diphenylphosphino)phenyl] ether (dpephos) was employed for selective room temperature hydroboration of nitro compounds with HBPin (TOF up to 4615 h?1), tolerating halide, hydroxy, amino, ether, ester, lactone, amide and heteroaromatic functionalities. These reactions offered a direct access to a variety of N-borylamines RN(H)BPin, which were in situ treated with aldehydes and carboxylic acids to produce a series of aldimines and secondary carboxamides without the need for dehydrating and/or coupling reagents. Combination of these transformations in a sequential one-pot manner allowed for direct and selective synthesis of aldimines and secondary carboxamides from readily available and inexpensive nitro compounds.
Tungsten-Catalyzed Transamidation of Tertiary Alkyl Amides
Feng, Fang-Fang,Liu, Xuan-Yu,Cheung, Chi Wai,Ma, Jun-An
, p. 7070 - 7079 (2021/06/30)
Transamidation has recently emerged as a straightforward and convenient means to diversify amides. However, the kinetically and thermodynamically demanding transamidation of notoriously robust, fully alkyl-substituted tertiary amides still remains a longstanding challenge. Here, we describe a method for the activation of tertiary alkyl amides to streamline transamidation using simple tungsten(VI) chloride as a catalyst and chlorotrimethylsilane as an additive. The highly electrophilic and oxophilic tungsten catalyst enables the selective scission of a C-N bond of tertiary alkyl amides to effect transamidation of a myriad of structurally and electronically diverse tertiary alkyl amides and amines. Mechanistic study implies that the synergistic effect of the catalyst and the additive could pronouncedly induce the nucleophilic acyl substitution of tertiary alkyl amide with amine to realize transamidation.
Dehydrative Beckmann rearrangement and the following cascade reactions
Liu, Yinghui,Wei, Yongjiao,Xie, Lan-Gui
supporting information, (2021/11/16)
The Beckmann rearrangement has been predominantly studied for the synthesis of amide and lactam. By strategically using the in situ generated Appel's salt or Mitsunobu's zwitterionic adduct as the dehydrating agent, a series of Beckmann rearrangement and following cascade reactions have been developed herein. The protocol allows the conversion of various ketoximes into amide, thioamide, tetrazole and imide products in modular procedures. The generality and tolerance of functionalities of this method have been demonstrated.
Preparation method of amide
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Paragraph 0055-0079; 0170-0175, (2021/08/25)
The invention relates to a preparation method of an amide, wherein, under the action of oxygen, the isothiocyanate and the aldehyde can react to form an amide, and the reaction temperature can be effectively increased only when not less than 110 °C. This process is also suitable for the reaction of isocyanates with aldehydes to produce amides. The preparation method is cheap in raw material, wide in substrate application range and free of metal catalysts in the reaction process. The initiator or other activator is green and economical, and can effectively reduce the cost.
