Saini Kapil Mohan, Saunthwal Rakesh K, Kumar Shiv, Verma Akhilesh K
Synthetic Organic Chemistry Research Laboratory, Department of Chemistry , University of Delhi , Delhi 110007 , India.
J Org Chem. 2019 Mar 1;84(5):2689-2698. doi: 10.1021/acs.joc.8b03107. Epub 2019 Feb 15.
An environmentally benign, transition-metal-free organic base promoted one-pot cascade synthesis of highly functionalized benzo[ d]thiazol-2(3 H)-ylidene benzamide in the presence of water was accomplished by three-component reaction of ortho-iodoanilines, acrylates, and aroyl isothiocyanates. The protocol involves the in situ generation of thiourea intermediate followed by triethylamine induced intramolecular SN displacement reaction and subsequent Michael addition onto acrylate leads to the formation of benzo[ d]thiazol-2(3 H)-ylidene benzamide. Benzo[ b]thiazole is also generated in good yields using amidation and intramolecular aromatic nucleophilic substitution chemistry. The control experiments support the proposed mechanistic pathway. Further X-ray crystallographic studies confirmed the assigned structures of the fused benzamide.
在水的存在下，通过邻碘苯胺、丙烯酸酯和芳酰基异硫氰酸酯的三组分反应，实现了一种环境友好的、无过渡金属的有机碱促进的一锅法串联合成高官能化苯并[d]噻唑-2(3H)-亚基苯甲酰胺。该方法涉及原位生成硫脲中间体，随后三乙胺诱导分子内SN取代反应，以及随后对丙烯酸酯的迈克尔加成，从而形成苯并[d]噻唑-2(3H)-亚基苯甲酰胺。使用酰胺化和分子内芳族亲核取代化学也能以良好的产率生成苯并[b]噻唑。对照实验支持所提出的反应机理途径。进一步的X射线晶体学研究证实了稠合苯甲酰胺的指定结构。
