1967-26-6Relevant articles and documents
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Hegarty,Frost
, p. 500 (1972)
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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.
Hydroamination of isocyanates and isothiocyanates by alkaline earth metal initiators supported by a bulky iminopyrrolyl ligand
Bano, Kulsum,Anga, Srinivas,Jain, Archana,Nayek, Hari Pada,Panda, Tarun K.
supporting information, p. 9419 - 9428 (2020/06/17)
A series of new heteroleptic alkaline earth (Ae) metal complexes of general formula [{(Ph2CHN-CH)2C4H2N}AeI(THF)3] {Ae = Ca (2), Sr (3), and Ba (4)} were synthesizedviasalt metathesis by reacting potassium salt of ligand1-K[{(Ph2CHN-CH)2C4H2N}K(THF)2] with anhydrous alkaline earth metal diiodides (AeI2). The homoleptic calcium and barium complexes [{(Ph2CHN-CH)2C4H2N}2Ae] [Ae = Ca (5), Ba (6)] were prepared by treating metal bis-hexamethyldisilazide [Ae{N(SiMe3)2}2(THF)2] with the protic ligand1-H[(Ph2CH-N-CH)2C4H2NH] in a 1:2 molar ratio. Calcium complex5was used as an active pre-catalyst for the addition of N-H bond of arylamines across the heterocumulenes such as phenylisocyanate (PhNCO) and phenylisothiocyanate (PhNCS) under neat conditions, and up to 99% yields of the corresponding urea and thiourea derivatives were obtained.
