title: Approach for 2-(arylthio)imidazoles and imidazo[2,1-b]thiazoles from imidazo[2,1-b][1,3,4]thiadiazoles by ring-opening and -reconstruction.
abstract: A highly efficient one-pot synthesis of imidazo[2,1-b]thiazole derivatives has been developed and proceeds via a ring-opening and ring-closing reconstruction of imidazo[2,1-b][1,3,4]thiadiazoles with phenylacetylene in the presence of potassium tert-butoxide (t-BuOK) under very mild reaction conditions. A proposed mechanism is calculated computationally using a DFT method at the B3LYP/6-31+G(d,p) level. The imidazo[2,1-b][1,3,4]thiadiazoles are also successfully converted to a series of 2-(arylthio)-1H-imidazoles using aryl halide as a reactant and copper(ii) acetylacetonate (Cu(acac)2) as a catalyst under microwave irradiation conditions. The key features of these reactions are the use of readily available reagents, simple operation, the convenient utilization of new heterocyclic synthons, and a great variety of substrates with functional group compatibility.
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China.
authors.forename: Benyi
authors.initials: B
authors.lastname: Shi
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China.
authors.forename: Zhouhe
authors.initials: Z
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China.
authors.forename: Yi-Shuo
authors.initials: YS
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China.
authors.forename: Dagang
authors.initials: D
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China.
authors.forename: Jinyuan
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China.
authors.forename: Panpan
authors.initials: P
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, P. R. China and State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan 030001, P. R. China. hw-jing@163.com.
authors.forename: Huanwang
authors.initials: H
authors.lastname: Jing