Title
Copper(II)- and gold(III)-mediated cyclization of a thiourea to a substituted 2-aminobenzothiazole
Document Type
Article
Publication Date
9-25-2017
Department
Chemistry
Abstract
Benzothiazole derivatives are a class of privileged molecules due to their biological activity and pharmaceutical applications. One route to these molecules is via intramolecular cyclization of thioureas to form substituted 2-aminobenzothiazoles, but this often requires harsh conditions or employs expensive metal catalysts. Herein, the copper(II)- and gold(III)-mediated cyclizations of thioureas to substituted 2-aminobenzothiazoles are reported. The single-crystal X-ray structures of the thiourea N-(3-methoxyphenyl)-N'- (pyridin-2-yl)thiourea, C13H13N3OS, and the intermediate metal complexes aquabis[5-methoxy-N-(pyridin-2-yl-κN)-1,3-benzothiazol-2-amine-κN3]copper(II) dinitrate, [Cu(C13H11N3OS)2(H2O)](NO3)2, and bis{2-[(5-methoxy-1,3-benzothiazol- 2-yl)amino]pyridin-1-ium} dichloridogold(I) chloride monohydrate, (C13H12N3OS)2[AuCl2]Cl⋅H2O, are reported. The copper complex exhibits a distorted trigonal–bipyramidal geometry, with direct metal-to-benzothiazoleligand coordination, while the gold complex is a salt containing the protonated uncoordinated benzothiazole, and offers evidence that metal reduction (in this case, AuIII to AuI) is required for the cyclization to proceed. As such, this study provides further mechanistic insight into the role of the metal cations in these transformations.
Recommended Citation
Schroeder, Z.W., Hiscock, L.K., and Dawe, L.N. (2017) Copper(II)- and gold(III)-mediated cyclization of a thiourea to a substituted 2-aminobenzothiazole. Acta Crystallographica Section C: Structural Chemistry, C73, 905-910. DOI: https://doi.org/10.1107/S205322961701381X
Comments
This article was originally published in Acta Crystallographica Section C, C73, 101-127. © 2017 the authors. Reproduced with permission.