14309-89-8Relevant academic research and scientific papers
Sulfur-Promoted Redox Cyclization of 2,2′-Dinitrodiphenyl Disulfides and Benzylamines
Teramoto, Masahiro,Imoto, Mitsutaka,Takeda, Motonori,Mizuno, Takumi,Nomoto, Akihiro,Ogawa, Akiya
, p. 2485 - 2493 (2021/04/15)
This study aims to develop green and sustainable advanced synthetic methods based on redox cyclization. Elemental sulfur is shown to promote the efficient synthesis of 2-substituted benzothiazoles from 2,2′-dinitrodiphenyl disulfides and benzylamines via redox cyclization in the absence of transition-metal catalysts and solvents. The 2-substituted benzothiazoles are obtained in good to excellent yields. This synthetic methodology is highly atom-economical and does not require any external oxidizing and/or reducing agents.
NaOTs-promoted transition metal-free C-N bond cleavage to form C-X (X = N, O, S) bonds
Chen, Wei,Liu, Sicheng,Liu, Tingting,Majeed, Irfan,Ye, Xiaojing,Zeng, Zhuo,Zhang, Yuqi,Zhu, Yulin
supporting information, p. 8566 - 8571 (2021/10/20)
Multifunctional transformation of amide C-N bond cleavage is reported. The protocol applies to benzamide, thioamide, alcohols, and mercaptan under similar reaction conditions catalyzed by NaOTs. It is noteworthy that NaOTs can not only be recycled and reused for up to three cycles without significant loss in catalytic activity, but also catalyze gram-grade reactions. This study provides a novel solution with mild conditions and a simple procedure for transformation of multiple amides.
PHOTOCATALYTIC SYSTEM AND APPLICATIONS THEREOF
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Page/Page column 30; 31, (2019/05/15)
The present invention relates to novel poly(heptazine imides), a photocatalytic system comprising such poly(heptazine imides) and a sulfur source as well as the application thereof in photocatalytic reactions.
Ionic liquid catalysed aerobic oxidative amidation and thioamidation of benzylic amines under neat conditions
Joshi, Abhisek,Kumar, Rahul,Semwal, Rashmi,Rawat, Deepa,Adimurthy, Subbarayappa
supporting information, p. 962 - 967 (2019/03/11)
Tetrabutylammonium hydroxide (TBAOH) was discovered as a highly efficient and green catalyst for aerobic oxidation of the α-methylene carbon of primary amines as well as benzylic groups into the corresponding amides and ketones under neat conditions. We described herein, ionic liquid TBAOH catalysed aerobic oxidation of benzyl amines to benzamides and with elemental sulfur; the corresponding benzylbenzothioamides were obtained under metal-free, oxidant-free and base-free conditions. Applicability at the gram scale for the synthesis of the desired amides/ketones is also demonstrated with the present protocol.
Sulfur-Catalyzed Oxidative Coupling of Dibenzyl Disulfides with Amines: Access to Thioamides and Aza Heterocycles
Nguyen, Thanh Binh,Nguyen, Le Phuong Anh,Nguyen, Thi Thu Tram
supporting information, p. 1787 - 1791 (2019/02/26)
In the presence of catalytic amounts of elemental sulfur, dibenzyl disulfide/DMSO was found to be an excellent thiobenzoylating agent of amines to provide a wide range of thioamides. The reaction becomes autocatalytic when anilines substituted by an o-cyclizable group were used as nucleophile, leading to the corresponding 2-aryl aza heterocycles. (Figure presented.).
Microwave-Assisted iodine-catalyzed oxidative coupling of dibenzyl(difurfuryl)disulfides with amines: A rapid and efficient protocol for thioamides
Chen, Jinyang,Mei, Lan,Liu, Jialing,Zhong, Chuntao,Yuan, Binfang,Li, Qiang
, p. 28576 - 28580 (2019/09/30)
An efficient protocol for synthesis of thioamides was developed via the microwave-Assisted iodine-catalyzed oxidative coupling of dibenzyl(difurfuryl)disulfides with amines. This process is scalable and tolerates a wide spectrum of amines to deliver the corresponding products in moderate to excellent yields in 10 minutes, providing a cheap and rapid approach to thioamides.
Graphene Oxide: A Metal-Free Carbocatalyst for the Synthesis of Diverse Amides under Solvent-Free Conditions
Patel, Khushbu P.,Gayakwad, Eknath M.,Patil, Vilas V.,Shankarling, Ganapati S.
supporting information, p. 2107 - 2116 (2019/03/26)
An environmentally friendly, inexpensive, carbocatalyst, graphene oxide (GO) promoted efficient, metal-free transamidation of various carboxamides with aliphatic, cyclic, and aromatic amines is demonstrated. The protocol is equally applicable to phthalimide, urea, and thioamide determining its adaptability. The oxygenated functionalities such as carbonyl (?C=O), epoxy (?O?), carboxyl (?COOH) and hydroxyl (?OH), present on graphene oxide surface impart acidic properties to the catalyst. The graphene oxide being heterogeneous in nature, work efficiently under solvent-free reaction conditions providing desired products in good to excellent yields. The one-pot synthesis of 2,3-Dihydro-5H-benzo[b]-1,4-thiazepin-4-one moiety by GO catalyzed Aza Michael addition followed by intramolecular transamidation is also described. A plausible reaction mechanistic pathway involving H-bonding is discussed. The graphene oxide can be recycled and reused up to five cycles without much loss in catalytic activity. (Figure presented.).
Oxidative Coupling-Thionation of Amines Mediated by Iron-Based Imidazolium Salts for the Preparation of Thioamides
Gisbert, Patricia,Pastor, Isidro M.
, p. 3031 - 3040 (2018/07/06)
An efficient and selective multicomponent oxidative coupling, involving the use of two different amines, sodium phosphate, and elemental sulfur have been described for the preparation of thioamides, employing microwave irradiation. The use of an iron(III)-based imidazolium salt is essential as catalyst. Indeed, the iron-based catalyst is involved in the oxidative coupling of the two amines and in the subsequent C-S bond formation. The protocol is useful for a wide variety of primary benzylamines and alkylamines, as coupling partners. Thus, various electron-rich and electron-poor substituents in the aromatic rings and also fused piperidine derivatives, are suitable starting materials in this reaction. Some of the obtained products are important synthetic intermediates for natural products.
Carbon nitride creates thioamides in high yields by the photocatalytic Kindler reaction
Kurpil,Kumru,Heil,Antonietti,Savateev
supporting information, p. 838 - 842 (2018/03/05)
Potassium poly(heptazine imide), a carbon nitride based photocatalyst, effectively promotes the Kindler reaction of thioamide bond formation using amines and elemental sulfur as building blocks under visible light irradiation. The feasibility of the developed methodology was confirmed using 14 different primary and secondary amines, including substituted benzylamines and heterocyclic and aliphatic methylamines, which were successfully converted into thioamides with 68-92% isolated yields.
Transition metal-free, chemoselective arylation of thioamides yielding aryl thioimidates or N-aryl thioamides
Villo, Piret,Kervefors, Gabriella,Olofsson, Berit
supporting information, p. 8810 - 8813 (2018/08/17)
Reactions of secondary thioamides with diaryliodonium salts under basic, transition metal-free conditions resulted in chemoselective S-arylation to provide aryl thioimidates in good to excellent yields. Equimolar amounts of thioamide, base and diaryliodonium salt were sufficient to obtain a diverse selection of products within short reaction times. Reactions with thiolactams delivered N-arylated thioamides in good yield at room temperature.
