Regioselective Transition-Metal-Free Synthesis of Diverse Benzothiazoles by Thermally Induced Cyclization ofortho-Halobenzanilides
| Autor: | Dae Yoon Chi, Byoung Se Lee, Ho Rim Song, Keun Sam Jang, Dong Seok Shin |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
Bromine
010405 organic chemistry Chemistry Substituent Regioselectivity chemistry.chemical_element General Chemistry 010402 general chemistry 01 natural sciences Combinatorial chemistry 0104 chemical sciences Metal chemistry.chemical_compound Transition metal Benzothiazole Cascade reaction visual_art visual_art.visual_art_medium Molecule Organic chemistry |
| Zdroj: | ChemistrySelect. 2:7227-7232 |
| ISSN: | 2365-6549 |
| DOI: | 10.1002/slct.201701130 |
| Popis: | The highly regioselective and efficient synthesis of diverse substituted-benzothiazoles, including heterocyclic units and amino groups, was achieved in moderate to high yields from ortho-bromothiobenzanilides, ortho-bromoarylthioureas, ortho-bromobenzanilides, and ortho-dibromobenzanilides, regardless of the electron density and substituted positions, via the prevalent carbon-sulfur bond formation by thermally induced intramolecular cyclization reaction without using any metal sources or other additives. Polysubstituted-benzothiazoles, particularly 2,4-, 2,6-disubstituted, and 2,4,6-trisubstituted benzothiazoles, could be efficiently synthesized by a facile cascade reaction from appropriate ortho-bromobenzanilides under general thiolation conditions. This benign reaction represents a straightforward and practical approach toward diverse substituted-benzothiazoles. In addition, the remaining bromine substituent of the resulting products was further utilized as a functional handle for the additional diversification and exploited as a complementary solution for the adjustment of harsh reaction condition. This methodology not only allows for the elaboration of benzothiazole molecules, but also provides a new valuable synthetic tool for a range of pharmaceutical applications. |
| Databáze: | OpenAIRE |
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