Cu(<scp>ii</scp>) catalysed chemoselective oxidative transformation of thiourea to thioamidoguanidine/2-aminobenzothiazole
作者:Santosh K. Sahoo、Nilufa Khatun、Anupal Gogoi、Arghya Deb、Bhisma K. Patel
DOI:10.1039/c2ra22240j
日期:——
o-halogens (–F, –Cl) gave 2-aminobenzothiazoles via a dehalogenative heteroarylation path and not by the Hugerschoff path involving an electrophilicsubstitutionreaction. For thioureas containing reactive ortho halogens (such as –Br, –I) the reaction proceeds at room temperature giving 2-aminobenzothiazoles via a dehalogenative path requiring a catalytic quantity of Cu(II). No transformation of thiourea (Tu)
Ph<sub>3</sub>P/I<sub>2</sub>-Mediated Synthesis of <i>N,N</i>′<i>,N</i>″-Substituted Guanidines and 2-Iminoimidazolin-4-ones from Aryl Isothiocyanates
A convenient one-pot procedure for the synthesis of acyclic and cyclic guanidines mediated by the Ph3P/I2 system is described. Sequential condensation of aryl isothiocyanates with amines followed by dehydrosulfurization and guanylation could lead to both symmetric and unsymmetric N,N′,N″-substituted derivatives. Through a tandem guanylation–cyclization, a series of 2-iminoimidazolin-4-ones could also
描述了一种方便的一锅法,用于合成由Ph 3 P / I 2系统介导的无环和环状胍。芳基异硫氰酸酯与胺的顺序缩合,然后进行脱氢硫化和鸟苷化,可能同时导致对称和不对称的N,N ' ,N '' -取代的衍生物。通过串联的胍基化-环化反应,还可以从芳基异硫氰酸酯与氨基酸甲酯的反应中以高收率制备一系列2-iminoimidazolin-4-ones。
Arylthioureas with bromine or its equivalents gives no ‘Hugerschoff’ reaction product
作者:Ramesh Yella、Siva Murru、Abdur Rezzak Ali、Bhisma K. Patel
DOI:10.1039/c003892j
日期:——
The in situ generated arylâalkyl unsymmetrical thiourea obtained by the reaction of an aryl isothiocyanate with an aliphatic secondary amine on treatment with bromine or its equivalent gave exclusively a product having a thioamido guanidino moiety and not the expected Hugerschoff product 2-aminobenzothiazole. A plausible reaction mechanism has been proposed for this unprecedented transformation and the scope has been extended to various substrates.