1145-66-0Relevant academic research and scientific papers
Nitroarenes as versatile building blocks for the synthesis of unsymmetrical urea derivatives and N-Arylmethyl-2-substituted benzimidazoles
Rodríguez-Huerto, Paula A.,Pe?a-Solórzano, Diana,Ochoa-Puentes, Cristian
, p. 6275 - 6283 (2021/07/29)
In this contribution, a fast and simple method for the synthesis of unsymmetrical urea derivatives and N-arylmethyl-2-substituted benzimidazoles was developed starting from nitroarenes. The reaction of nitroarenes and phenyl isocyanate or phenyl isothiocyanate in tin (II) chloride dihydrate/choline chloride eutectic mixture afforded the expected urea and thiourea derivatives, while the reaction of different aldehydes with o-nitroaniline or 4-methoxy-2-nitroaniline shows a markedly high preference for the obtention of N-arylmethyl-2-substituted benzimidazoles over the 2-substituted analogues. This method offers a straightforward alternative to obtain the target compounds in good to excellent yields with short reaction times employing an operationally simple experimental set-up. Graphic abstract: [Figure not available: see fulltext.] A series of unsymmetrical urea and thiourea derivatives together with 1,2-disubstituted benzimidazoles are easily obtained in good yields starting from nitroarenes employing the eutectic mixture tin (II) chloride dihydrate/choline chloride as reductive reaction media.
Hydroamination and Hydrophosphination of Isocyanates/Isothiocyanates under Catalyst-Free Conditions
Zhu, Xiancui,Xu, Mengchen,Sun, Jinrong,Guo, Dianjun,Zhang, Yiwei,Zhou, Shuangliu,Wang, Shaowu
, p. 5213 - 5218 (2021/10/19)
Symmetrical and unsymmetrical N,N’-disubstituted as well as trisubstituted ureas/thioureas by the hydroamination of isocyanates/isothiocyanates, and various phosphathioureas by the hydrophosphination of isothiocyanates have been synthesized in good to excellent yields under catalyst-free and mild conditions. This protocol is also applicable for the efficient synthesis of chiral ureas and thioureas and common herbicides, such as fenuron and monuron.
Tunable NIR-II emitting silver chalcogenide quantum dots using thio/selenourea precursors: Preparation of an MRI/NIR-II multimodal imaging agent
Basel, Siddhant,Bhardwaj, Karishma,Borthakur, Sukanya,Brito, Beatriz,Clarke, Mitchell,Pariyar, Anand,Pradhan, Sajan,Roy, Pankaj,Saikia, Lakshi,Shankar, Amit,Stasiuk, Graeme J.,Tamang, Sudarsan,Thapa, Surakcha
supporting information, p. 15425 - 15432 (2020/11/18)
Aqueous-stable, Cd- and Pb-free colloidal quantum dots with fluorescence properties in the second near-infrared region (NIR-II, 1000-1400) are highly desirable for non-invasive deep-tissue optical imaging and biosensing. The low band-gap semiconductor, silver chalcogenide, offers a non-toxic and stable alternative to existing Pd, As, Hg and Cd-based NIR-II colloidal quantum dots (QDs). We report facile access to NIR-II emission windows with Ag2X (X = S, Se) QDs using easy-to-prepare thio/selenourea precursors and their analogues. The aqueous phase transfer of these QDs with a high conservation of fluorescence quantum yield (retention up to ~90%) and colloidal stability is demonstrated. A bimodal NIR-II/MRI contrast agent with a tunable fluorescence and high T1 relaxivity of 408 mM-1 s-1 per QD (size ~ 2.2 nm) and 990 mM-1 s-1 per QD (size ~ 4.2 nm) has been prepared by grafting 50 and 120 monoaqua Gd(iii) complexes respectively to two differently sized Ag2S QDs. The size of the nanocrystals is crucial for tuning the Gd payload and the relaxivity.
Synthesis and Reactivity of NNNNN-Pincer Multidentate Pyrrolyl Rare-Earth-Metal Amido-Chloride or Dialkyl Complexes
Cui, Peng,Du, Jun,Huang, Zeming,Sheng, Weiming,Wang, Shaowu,Wei, Yun,Xu, Xiaolong,Zhang, Lijun,Zhang, Xiuli,Zhou, Shuangliu,Zhu, Xiancui
supporting information, p. 4525 - 4534 (2020/12/22)
The NNNNN-pincer multidentate pyrrolyl rare-earth-metal amido-chloride complexes {η1:κ3-2,5-[CH3N(CH2CH2)2NCH2]2C4H2N}RECl[N(SiMe3)2] (RE = Y (2a), Sm (2b), Dy (2c), Er (2d), Yb (2e)) were synthesized by one step from reactions of [(Me3Si)2N]3RE(μ-Cl)Li(T
One-pot synthesis of highly functionalized benzo [1,3] thiazine from isocyanides, aniline, and heterocumulene via Cu-catalyzed intramolecular C-H activation reactions
Dastjerdi, Hossein F.,Nematpour, Manijeh,Rezaee, Elham,Jahani, Mehdi,Tabatabai, Sayyed A.
, p. 1537 - 1541 (2019/07/12)
A one-pot synthesis of functionalized benzo thiazine derivatives via a Cu-catalyzed, multicomponent reaction of isocyanides, aniline, and heterocumulenes in acetonitrile at room temperature was developed. Transition metal-catalyzed activation of C-H bonds
A facile method for the preparation of carbodiimides from thioureas and (Boc)2O
Wu, He,Sun, Yan-Fang,Zhang, Chen,Miao, Chun-Bao,Yang, Hai-Tao
supporting information, p. 739 - 742 (2018/01/27)
A concise method for the preparation of carbodiimides from thioureas using di-tert-butyl dicarbonate [(Boc)2O] as the dehydrosulfurizative reagent has been developed. Using DMAP as the catalyst, a variety of symmetric and asymmetric 1,3-diaryl thioureas were converted into the corresponding carbodiimides efficiently in a short time.
Palladium catalyzed carbonylative annulation of the C(sp2)-H bond of N,1-diaryl-1H-tetrazol-5-amines and N,4-diaryl-4H-triazol-3-amines to quinazolinones
Chandrasekhar, Attoor,Ramkumar, Venkatachalam,Sankararaman, Sethuraman
supporting information, p. 8629 - 8638 (2018/12/12)
Pd(ii) catalyzed direct C-H carbonylative annulation of N,1-diaryl-1H-tetrazol-5-amines and N,4-diaryl-4H-1,2,4-triazol-3-amines gave the corresponding triazole and tetrazole fused quinazolinones in good yields. This methodology offers a convenient method for the synthesis of these important heterocyclic scaffolds in a highly atom economical process. On the mechanistic aspect weakly nucleophilic triazole and tetrazole moieties function as both directing as well as intramolecular nucleophiles. The catalytically active C-H activated intermediate dimeric Pd complex was isolated and characterized which on exposure to CO gas gave the corresponding tetrazole fused quinazolinone derivative. On the basis of isolation of the intermediate and observed kinetic isotope effects, a mechanism has been proposed for the C-H activated direct carbonylative annulation reaction.
Nickle Catalysis Enables Access to Thiazolidines from Thioureas via Oxidative Double Isocyanide Insertion Reactions
Yuan, Wen-Kui,Liu, Yan Fang,Lan, Zhenggang,Wen, Li-Rong,Li, Ming
supporting information, p. 7158 - 7162 (2018/11/25)
An efficient synthesis of thiazolidine-2,4,5-triimine derivatives was developed via Ni-catalyzed oxidative double isocyanide insertion to thioureas under air conditions, in which thioureas play three roles as a substrate, a ligand, and overcoming isocyanide polymerization. The reaction is featured by employing a low-cost and low loading Ni(acac)2 catalyst, without any additives, and high atom economy. This is the first example to directly apply a Ni(II) catalyst in oxidative double isocyanide insertion reactions.
An isocyanide based multi-component reaction under catalyst- and solvent-free conditions for the synthesis of unsymmetrical thioureas
Singh, Karandeep,Sharma, Siddharth
, p. 197 - 201 (2016/12/28)
A new and efficient method for the synthesis of thiourea derivatives by a sequential one-pot, three-component reaction between aromatic isocyanides, amines, and 1,2-di-tert-butyldisulfane (DTBS) was developed and 27 different examples were synthesized in good to excellent yields. DTBS was identified as an effective sulfur surrogate without the use of both catalysts and solvents. This protocol does not employ any transition metal catalyst or special experimental setup.
Dual roles of substituted thiourea as reductant and ligand in CuAAC reaction
Wang, Siyu,Jia, Kai,Cheng, Jiajia,Chen, Yu,Yuan, Yaofeng
supporting information, p. 3717 - 3721 (2017/09/01)
A highly efficient catalytic system, CuSO4·5H2O/1-(4-methoxyphenyl)-3-phenylthiourea, for the copper(I)-catalyzed azide–alkyne cycloaddition reaction (CuAAC) was discovered. In the above catalytic system, substituted thiourea acts both as a reductant and a ligand. CuSO4·5H2O/1-(4-methoxyphenyl)-3-phenylthiourea is both an economical and efficient catalyst for the CuAAC reaction. In addition, the new catalytic system has advantageous features including mild and green reaction conditions, and broad substrate compatibility. A variety of 1,4-disubstituted 1,2,3-triazoles have been prepared with good to excellent yields with the CuSO4·5H2O/1-(4-methoxyphenyl)-3-phenylthiourea catalytic system in aqueous solution.
