- Zn, Cd and Hg complexes with unsymmetric thiourea derivatives; syntheses, free radical scavenging and enzyme inhibition essay
-
Unsymmetrical thiourea of general formula RR'C[dbnd]S where R ≠ R′, were prepared by treating phenyisothiocayanate with iso-butylamine and tert-butylamine and respective thiourea derivatives, isobutylphenylthiourea (1) and tert-butylphenylthiourea (2) wer
- Rahman, Faizan Ur,Bibi, Maryam,Altaf, Ataf Ali,Tahir, Muhammad Nawaz,Ullah, Farhat,Zia-Ur-Rehman,Khan, Ezzat
-
-
Read Online
- Hydroamination and Hydrophosphination of Isocyanates/Isothiocyanates under Catalyst-Free Conditions
-
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.
- Zhu, Xiancui,Xu, Mengchen,Sun, Jinrong,Guo, Dianjun,Zhang, Yiwei,Zhou, Shuangliu,Wang, Shaowu
-
p. 5213 - 5218
(2021/10/19)
-
- Micelle-Enabled One-Pot Guanidine Synthesis in Water Directly from Isothiocyanate using Hypervalent Iodine(III) Reagents under Mild Conditions
-
In this work, we developed a one-pot synthesis of guanidine directly from isothiocyanate using DIB (diacetoxyiodobenzene) as a desulfurizing agent under micellar conditions in water. Our optimization study revealed that the use of 1 % TPGS-750-M as a surfactant with NaOH as an additive base at room temperature can convert a variety of isothiocyanates and amines into corresponding guanidines in excellent yields (69–95 %). This synthetic process in water can be applied to prepare guanidine at gram-scale quantity. Our aqueous micellar medium also demonstrated high reusability as the reaction can be performed for several cycles without losing its efficiency. The reaction is metal-free, utilizes water as solvent and practical (room temperature and open flask).
- Srisa, Jakkrit,Tankam, Theeranon,Sukwattanasinitt, Mongkol,Wacharasindhu, Sumrit
-
p. 3335 - 3343
(2019/09/12)
-
- 2-Picolylamino(diphenylphosphinoselenoic)amide supported zinc complexes: Efficient catalyst for insertion of N–H bond into carbodiimides, isocyanates, and isothiocyanate
-
We report here the hydroamination of heterocumulenes such as carbodiimides, isocyanates, and isothiocyanates by zinc complexes supported by the ligand 2-picolylamino-(diphenylphosphinoselenoic)amide [{(Ph2P-(?Se)}2NCH2(C5H4N)] (1). A series of zinc complexes [κ2-{(Ph2P-(?Se)}2NCH2(C5H4N)ZnX2] [(X?Cl (2), Br (3a), I (4)] were prepared from ligand 1 and the corresponding zinc dihalide in a 1:1 molar ratio at 60°C in a chloroform solvent. The reaction of ligand 1 and ZnBr2 in methanol yielded another zinc complex [κ2-{(Ph2P-(?Se)}2NCH2(C5H4N)ZnBr2(CH3OH)] (3b). The molecular structures of compounds 3a, 3b, and 4 were established through single-crystal X-ray diffraction analyses. The solid-state structures of all the complexes revealed a κ2- chelation through pyridine nitrogen and selenium atoms of ligand 1 to the zinc ion. Complex 2 proved to be a competent pre-catalyst for the addition of the amine N–H bond to carbodiimides, isocyanates, and isothiocyanates. The reaction scope was expanded to reactions of aliphatic and aromatic amines with phenylisocyanate and phenylisothiocyanate in toluene solvents, which proceeded rapidly at room temperature with 5 mol% catalyst loading to yield (up to 99%) the corresponding derivatives of urea and thio-urea. However, a temperature of 90°C was needed for the hydroamination of N,N′ dicyclohexylcarbodiimide. We also report the most plausible mechanism of the hydroamination reaction.
- Harinath, Adimulam,Bano, Kulsum,Ahmed, Shakil,Panda, Tarun K.
-
supporting information
p. 23 - 32
(2017/09/25)
-
- Hydroamination of carbodiimides, isocyanates, and isothiocyanates by a bis(phosphinoselenoic amide) supported titanium(IV) complex
-
The hydroamination of heterocumulenes such as carbodiimides, isocyanates, and isothiocyanates by a bis(phosphinoselenoic amide) supported titanium(iv) complex as a precatalyst is reported here. The titanium(iv) complex [{Ph2P(Se)NCH2CH2NPPh2(Se)}Ti(NMe2)2] (1) was synthesised by the reaction of tetrakis-(dimethylamido)titanium(iv) [Ti(NMe2)4] with [{Ph2P(Se)NHCH2CH2NHPPh2(Se)}] in toluene at ambient temperature. Titanium complex 1 proved to be a competent pre-catalyst for the addition of an amine N-H bond to carbodiimides, isocyanates, and isothiocyanates. The reaction scope was expanded to reactions of aliphatic and aromatic amines with phenylisocyanates and phenylisothiocyanates in toluene solvents proceeding rapidly at room temperature with 5 mol% catalyst loadings to yield the corresponding urea and thio-urea derivatives up to 99%. However, ambient temperature was needed for hydroamination of 1,3-dicyclohexylcarbodiimide. The amine addition reactions with isocyanates showed first order kinetics with respect to catalyst 1 as well as substrates. The most plausible mechanism for the hydroamination reaction was established by isolating 1,1-dimethylphenyl urea as a side product.
- Bhattacharjee, Jayeeta,Das, Suman,Kottalanka, Ravi K.,Panda, Tarun K.
-
supporting information
p. 17824 - 17832
(2016/11/18)
-
- Cerium ammonium nitrate-catalyzed aerobic oxidative coupling of dithiocarbamates: Facile synthesis of thioureas and bis(aminothiocarbonyl)disulfides
-
Diverse disubstituted and trisubstituted thioureas were synthesized by the condensation of dithiocarbamate TEA (or DABCO) salts and amines using cerium ammonium nitrate (CAN) as a catalyst in high yields at room temperature. It is a one-pot method and it is unnecessary to isolate isothiocyanates. This reaction probably took place through nucleophilic addition of amines to isothiocyanates, which were generated by oxidative coupling of dithiocarbamates and the following decomposition of bis(aminothiocarbonyl)disulfides. When secondary amines and CS2served as the reactants, bis(aminothiocarbonyl)disulfides were obtained via tandem nucleophilic addition/oxidative coupling reactions in moderate to excellent yields. In all the coupling reactions, the oxidant was air and CAN possibly acted as an SET catalyst.
- Li, Tian-Tian,Song, Xiang-Hai,Wang, Mei-Shuang,Ma, Ning
-
p. 40054 - 40060
(2014/12/10)
-
- Cobalt(II)-catalyzed isocyanide insertion reaction with amines under ultrasonic conditions: A divergent synthesis of ureas, thioureas and azaheterocycles
-
Cobalt(II) acetylacetonate-catalyzed isocyanide insertion reactions with amines utilizing tert-butyl hydroperoxide (TBHP) as an oxidant under ultrasound conditions have been developed, which lead to the synthesis of ureas, thioureas, as well as 2-aminoben
- Zhu, Tong-Hao,Xu, Xiao-Ping,Cao, Jia-Jia,Wei, Tian-Qi,Wang, Shun-Yi,Ji, Shun-Jun
-
supporting information
p. 509 - 518
(2014/05/20)
-
- Synthesis of thiazolidines via regioselective addition of unsymmetric thioureas to maleic acid derivatives
-
A wide range of unsymmetric thioureas has been studied in reaction with N-arylmaleimides and maleic anhydride. The regioselectivity of the addition depends not only on steric factors but on both solvent polarity and type of maleic acid derivative (imide o
- Pankova, Alena S.,Samartsev, Mikhail A.,Shulgin, Igor A.,Golubev, Pavel R.,Avdontceva, Margarita S.,Kuznetsov, Mikhail A.
-
p. 51780 - 51786
(2014/12/10)
-
- Ultrasound-promoted scavenging: A rapid parallel purification for solution phase combinatorial synthesis
-
Ultrasound irradiation enhances the mass transfer and reaction rate in scavenging, avoiding the trouble of time-consuming purification procedure in solution-phase parallel synthesis. An application of this technique is demonstrated in the scavenging of excess isothiocyanates from reaction mixtures.
- Peng, Yanqing,Song, Gonghua,Xu, Xiaoyong
-
p. 261 - 263
(2007/10/03)
-
- Synthesis and structure-activity relationships of novel phenylcyanoguanidine derivatives as potassium channel openers
-
3,5-Di-substituted phenylcyanoguanidine derivatives with halogen, cyano, and/or nitro groups at the 3- and 5-positions of the benzene ring exhibited very strong smooth muscle relaxation activity in vitro, as compared to pinacidil. Among them, N-(3-chloro-5-cyanophenyl)-N'-cyano-N''-tert- pentylguanidine (5s) showed 27-fold more potent activity than pinacidil, and exhibited a stronger and more lasting antihypertensive effect than pinacidil by oral administration to spontaneously hypertensive rats. We propose a new pharmacophore model in which the essential factors for binding to the potassium channel are an NH and a bulky alkyl group.
- Yoshiizumi, Kazuya,Ikeda, Shoji,Goto, Katsumi,Morita, Tominori,Nishimura, Noriyasu,Sukamoto, Takayuki,Yoshino, Kohichiro
-
p. 2042 - 2050
(2007/10/03)
-