636-04-4Relevant articles and documents
AMIDE AND THIOAMIDE BANDS OF BENZANILIDE AND THIOBENZANILIDE IN THE VIBRATIONAL SPECTRA
Petrov, I.,Grupce, O.
, p. 481 - 484 (1984)
It has been widely accepted that in secondary amides and secondary thioamides, in the spectral region between 1600 and 1200 cm-1 two characteristic bands could be recognized (Amide II and Amide III for amides and B and C bands for thioamides).Our spectra of benzanilide, C6H5(C=O)NHC6H5, and thiobenzanilide, C6H5(C=S)NHC6H5, show that in this region there are, at least, four prominent bands which shift on deuteration.That could indicate that all these bands are in connection with the vibrations of amide and/or thioamide groups.Some other amide and thioamide bands have been also discussed.
The structures of ring-expanded NHC supported copper(
Charman, Rex S. C.,Liptrot, David J.,Lowe, John P.,Mahon, Mary F.
supporting information, p. 831 - 835 (2022/02/01)
Three ring-expanded N-heterocyclic carbene-supported copper(i) triphenylstannyls have been synthesised by the reaction of (RE-NHC)CuOtBu with triphenylstannane (RE-NHC = 6-Mes, 6-Dipp, 7-Dipp). The compounds were characterised by NMR spectroscopy and X-ray crystallography. Reaction of (6-Mes)CuSnPh3 with di-p-tolyl carbodiimide, phenyl isocyanate and phenylisothiocyanate gives access to a copper(i) benzamidinate, benzamide and benzothiamide respectively via phenyl transfer from the triphenylstannyl anion with concomitant formation of (Ph2Sn)n. Attempts to exploit this reactivity under a catalytic regime were hindered by rapid copper(i)-catalysed dismutation of Ph3SnH to Ph4Sn, various perphenylated tin oligomers, H2 and a metallic material thought to be Sn(0). Mechanistic insight was provided by reaction monitoring via NMR spectroscopy and mass spectrometry.
An efficient and straightforward approach for accessing thionoesters: Via palladium-catalyzed C-N cleavage of thioamides
Liu, Yinbo,Mo, Xiaofeng,Majeed, Irfan,Zhang, Mei,Wang, Hui,Zeng, Zhuo
supporting information, p. 1532 - 1537 (2022/03/01)
We report for the first time the coupling of activated thioamides with alcohols to efficiently form thionoesters via a palladium-catalyzed C-N cleavage strategy. The new approach employs thioamides as a thioacylating reagent to give thionoesters in moderate to good yields. Notably, this methodology demonstrates a broad substrate scope, as alkyl/aryl alcohols are well tolerated, and this process might facilitate the synthesis of sulfur-containing compounds under simple and mild conditions. This journal is
Chemoselective Transamidation of Thioamides by Transition-Metal-Free N?C(S) Transacylation
Hong, Xin,Li, Guangchen,Szostak, Michal,Xing, Yangyang,Zhang, Jin,Zhao, Hui
, (2022/02/25)
Thioamides represent highly valuable isosteric in the strictest sense “single-atom substitution” analogues of amides that have found broad applications in chemistry and biology. A long-standing challenge is the direct transamidation of thioamides, a process which would convert one thioamide bond (R?C(S)?NR1R2) into another (R?C(S)?NR3N4). Herein, we report the first general method for the direct transamidation of thioamides by highly chemoselective N?C(S) transacylation. The method relies on site-selective N-tert-butoxycarbonyl activation of 2° and 1° thioamides, resulting in ground-state-destabilization of thioamides, thus enabling to rationally manipulate nucleophilic addition to the thioamide bond. This method showcases a remarkably broad scope including late-stage functionalization (>100 examples). We further present extensive DFT studies that provide insight into the chemoselectivity and provide guidelines for the development of transamidation methods of the thioamide bond.
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.
A chromatography-free and aqueous waste-free process for thioamide preparation with Lawesson's reagent
Wu, Ke,Ling, Yichen,Ding, An,Jin, Liqun,Sun, Nan,Hu, Baoxiang,Shen, Zhenlu,Hu, Xinquan
, p. 805 - 812 (2021/05/03)
After completing the thio-substitution with Lawesson's reagent, ethanol was found to be effective in the decomposition of the inherent stoichiometric six-membered-ring byproduct from the Lawesson's reagent to a highly polarized diethyl thiophosphonate. The treatment significantly simplified the following chromatography purification of the desired thioamide in a small scale preparation. As scaling up the preparation of two pincer-type thioamides, we have successfully developed a convenient process with ethylene glycol to replace ethanol during the workup, including a traditional phase separation, extraction, and recrystallization. The newly developed chromatography-free procedure did not generate P-containing aqueous waste, and only organic effluents were discharged. It is believed that the optimized procedure offers the great opportunity of applying the Lawesson's reagent for various thio-substitution reactions on a large scale.
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.
Transition-Metal-Free, General Construction of Thioamides from Chlorohydrocarbon, Amide and Elemental Sulfur
Chen, Xinzhi,Ge, Xin,Jin, Hao,Qian, Chao,Zhou, Shaodong
supporting information, p. 3403 - 3406 (2021/06/25)
A general method for one-pot synthesis of thioamides is developed through a three-component reaction involving chlorohydrocarbon, amide and elemental sulfur. Such a strategy does not only avoid residual transition metal in the product but also prevent the generation of C?N coupling by-product. The latter is prone to be generated when alkane halide and amine are present. With the protocol proposed in this work, both alkyl and aryl thioamides can be obtained in moderate to excellent yields with a high tolerance of various functional groups. External oxidants are not required in the reaction. In addition, the reaction mechanisms are addressed using a combination of controlling experiments and quantum chemical calculations.
Benzothiazole solid-state luminescent material as well as preparation method and application thereof
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Paragraph 0091; 0095-0096, (2020/10/05)
The invention provides a benzothiazole solid-state luminescent material as well as a preparation method and an application thereof, and relates to the technical field of solid-state luminescent materials. The benzothiazole solid-state luminescent material provided by the invention has a structure shown as a formula I, wherein Ar in the formula I is phenyl, naphthyl or anthryl. The benzothiazole solid-state luminescent material provided by the invention is good in color tone, saturation and color rendering property, high in luminous efficiency, and strong in light stability and chemical stability. As shown in the result of the embodiment of the invention, the chromaticity coordinate of the benzothiazole solid-state luminescent material provided by the invention is (0.27-0.28, 0.34-0.38), the color rendering index is 64-73, the color temperature is 8089-8341, and the lighting effect is 4.8-5.68 lm/W.
Exogenous Photosensitizer-, Metal-, and Base-Free Visible-Light-Promoted C-H Thiolation via Reverse Hydrogen Atom Transfer
Xu, Ze-Ming,Li, Hong-Xi,Young, David James,Zhu, Da-Liang,Li, Hai-Yan,Lang, Jian-Ping
supporting information, p. 237 - 241 (2019/01/10)
Visible-light-driven, intramolecular C(sp2)-H thiolation has been achieved without addition of a photosensitizer, metal catalyst, or base. This reaction induces the cyclization of thiobenzanilides to benzothiazoles. The substrate absorbs visible light, and its excited state undergoes a reverse hydrogen-atom transfer (RHAT) with 2,2,6,6-tetramethylpiperidine N-oxyl to form a sulfur radical. The addition of the sulfur radical to the benzene ring gives an aryl radical, which then rearomatizes to benzothiazole via RHAT.
