27779-01-7Relevant academic research and scientific papers
DIBENZOTHIOPHENE SALT AS ALKYNYLATING AND CYANATING AGENT
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Paragraph 0098, (2021/08/27)
The present invention describes a new alkynylation and cyanation agent, as well as its preparation and use to introduce nitrile (cyano) or alkyne groups into chemical target molecules by means of an electrophilic reaction. To enable an electrophilic reaction, the chemical backbone of dibenzothiophene was used.
Preparation method of cyano tertiary amine
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Paragraph 0078-0080, (2020/12/09)
The invention relates to the technical field of organic synthesis methods, in particular to a preparation method of N, N-disubstituted cyanamide. According to the invention, secondary amine and 2-bromo-1, 3, 4-thiadiazole, 2, 5-dibromo-1, 3, 4-thiadiazole or 2-bromo-5-methyl-1, 3, 4-thiadiazole are used as raw materials to prepare N, N-disubstituted cyano tertiary amine under the catalysis of a metal salt; the synthetic process is simple, the yield is high, the toxicity of the raw materials is extremely low, the reaction temperature is low, the reaction time is sort, the aftertreatment is simple, and the preparation process is a green preparation process with universality. The method for preparing N, N-disubstituted cyanamide solves the problems of low yield, high toxicity of raw materials, no universality, difficulty in asymmetric disubstituted synthesis and the like in the existing preparation process, and has industrial large-scale application prospects.
5-(Cyano)dibenzothiophenium Triflate: A Sulfur-Based Reagent for Electrophilic Cyanation and Cyanocyclizations
Li, Xiangdong,Golz, Christopher,Alcarazo, Manuel
supporting information, p. 9496 - 9500 (2019/06/27)
The synthesis of 5-(cyano)dibenzothiophenium triflate 9, prepared by activation of dibenzo[b,d]thiophene-5-oxide with Tf2O and subsequent reaction with TMSCN is reported, and its reactivity as electrophilic cyanation reagent evaluated. The scalable preparation, easy handling and broad substrate scope of the electrophilic cyanation promoted by 9, which includes amines, thiols, silyl enol ethers, alkenes, electron rich (hetero)arenes and polyaromatic hydrocarbons, illustrate the synthetic potential of this reagent. Importantly, Lewis acid activation of the reagent is not required for the transfer process. We additionally report herein biomimetic cyanocyclization cascade reactions, which are not promoted by typical electrophilic cyanation reagents, demonstrating the superior ability of 9 to trigger challenging transformations.
Transition-metal free N-arylation of cyanamides by diaryliodonium triflates in aqueous media
Li, Jihui,Zheng, Xinyi,Li, Wei,Zhou, Wei,Zhu, Wen,Zhang, Yucang
supporting information, p. 77 - 80 (2016/01/12)
An operationally simple protocol is established for the synthesis of disubstituted cyanamides through the transition-metal free N-arylation of cyanamides by diaryliodonium triflates in aqueous media. Both alkyl and aryl cyanamides are well compatible with the mild reaction conditions. The one-pot synthesis of ureas is also possible through sequential arylation and hydrolysis of cyanamides, diaryliodonium triflates and H2O with good yields.
Copper-catalyzed one-pot synthesis of unsymmetrical arylurea derivatives via tandem reaction of diaryliodonium salts with N -arylcyanamide
Li, Pengfei,Cheng, Guolin,Zhang, Hong,Xu, Xianxiang,Gao, Jingyuan,Cui, Xiuling
, p. 8156 - 8162 (2015/03/18)
An efficient "one-pot" approach to multiple substituted ureas from N-arylcyanamide and diaryliodonium salts has been presented. The two-step procedure involved the weak base-promoted chemoselective arylation of secondary amines with diaryliodonium and Cu-catalyzed nucleophilic addition of N-arylcyanamide with second diaryliodonium. The diverse unsymmetrical arylureas were obtained in up to 91% yield for 29 examples.
Quantitative gas-solid reactions with ClCN and BrCN: Synthesis of cyanamides, cyanates, thiocyanates, and their derivatives
Kaupp, Gerd,Schmeyers, Jens,Boy, Juergen
, p. 2467 - 2474 (2007/10/03)
Gas-solid reaction techniques allow quantitative cyanations with ClCN and BrCN. Three primary and four secondary cyanamides, a cyanimide, four cyanates, and four thiocyanates were all prepared as solids in 100% yield from solid anilines, benzimidazoles, imides, phenolates, and thiolates, respectively. Intramolecular solid-state reactions of cyanated o-aminophenol and of cyanated hydrazides gave heterocyclic compounds. When comparable reactions were performed in solution the reported product yields were considerably less than 100% in all cases. The reasons for the success of the environmentally benign solid-state syntheses are discussed in terms of phase rebuilding, phase transformation, and crystal disintegration. Atomic force microscopy (AFM) of selected systems indicates the occurrence of long-range molecular movements which are governed by the crystal packing. This is evident from the obvious correlations between the molecular movements and the known crystal packing data. A new type of geometric surface feature, a rectangular and a rhombic depression which resembles a swimming-pool basin, was found in the cyanation of o-aminophenol and benzohydrazide.
Mild and Efficient Dehydrosulfurization of Thioamides to Nitriles induced by Tellurium or Selenium Tetrachloride with Triethylamine
Aso, Yoshio,Omote, Kazushi,Takagi, Seitaro,Otsubo, Tetsuo,Ogura, Fumio
, p. 152 - 153 (2007/10/03)
Tellurium tetrachloride or selenium tetrachloride in combination with triethylamine reacts smoothly with primary thioamides at room temperature to give nitriles in very high yields.
Chemoselective Reactions of Tellurium Tetraethoxide towards Thioamides and Amides
Omote, Kazushi,Aso, Yoshio,Otsubo, Tetsuo,Ogura, Fumio
, p. 1759 - 1761 (2007/10/02)
Tellurium tetraethoxide reacts with primary thioamides at room temperature, forming nitriles in high yields. On the other hand, the reactions with amides are largely temperature-dependent, giving predominantly esters at 80 deg C and nitriles at a higher temperature. Similarly, tellurium tetraethoxide readily induces the C-N bond cleavage of ureas to give carbamates and amines.
THERMOLYSIS OF SOME THIOUREA DERIVATIVES
Gaber, Abd El-Aal M.,Aly, Morsy M.,Atalla, Ahmed A.
, p. 2183 - 2187 (2007/10/02)
Thermolysis of N-benzoyl-N',N'-diphenylthiourea (BDTU) (I) at 250 deg C gives NH3, H2S, H2O, benzaldehyde, benzil, benzonitrile, diphenylamine, diphenylcyanamide, 2-phenylbenzimidazole, benzoyl isothiocyanate, carbazole and 2-phenylbenzthiazole, whereas, thermolysis of N-benzoyl-N'-ο-tolylthiourea (BTTU) (II) under the same conditions affords NH3, H2S, H2O, benzaldehyde, benzil, benzonitrile, o-toluidine, o-tolyl isothiocyanate, o-tolylcyanamide, benzoyl isothiocyanate and N,N'-di-o-tolylthiourea.The main feature of these thermolyses is homolysis of the amide and thioamide bonds providing free radicals that undergo the common reactions involving H-abstraction, dimerization, coupling, fragmentation, rearrangement and cyclization.A suitable mechanism has been suggested to account for the observed products.
Comparison of chemical and electrochemical reduction of cyanamides:an exmple of cathodic decyanation
Cariou, Michel,Simonet, Jacques
, p. 861 - 864 (2007/10/02)
Most disubstituted cyanamides exhibit a very low cathodic activity and are therefore difficult to reduce.However, the cathodic cleavage of diarylcyanamides can be carried out directly and leads to the corresponding diarylamine; the action of sodium causes the same cleavage.Alkylarylcyanamides display no cathodic step, but can be reduced indirectly by redox catalysis; this allows the determination of the standard potential corresponding to the first electron transfer.The macroscale electrolysis, in the presence of the catalyst, leads to the alkylarylamine by cleavage, whereas the action of sodium gives mainly a cyanoguanidine.Dialkylcyanamides are electroreducible neither directly, nor indirectly, whereas by action of sodium they trimerize almost quantitatively into triazines. Key words: cyanamide, decyanation, electroreduction, redox catalysis.
