Facile access to libraries of diversely substituted 2-aryl-benzoxazoles/benzothiazoles from readily accessible aldimines via cyclization/cross coupling in imidazolium-ILs with Pd(OAc)2 or NiCl2 (dppp) as catalyst
作者:Shruti S. Malunavar、Suraj M. Sutar、Hemantkumar M. Savanur、Rajesh G. Kalkhambkar、Kenneth K. Laali
DOI:10.1016/j.tetlet.2019.151509
日期:2020.2
p-bromophenyl-aldimines to 2-bromophenyl-benzoxazole/benzothiazole in [BMIM][PF6] or [BMIM][BF4] as solvent, followed by the Suzuki, Heck, and Sonogashira cross-coupling reactions catalyzed by Pd or Ni is described that generates libraries of diversely substituted 2-aryl-/heteroaryl-benzoxazoles/benzothiazoles in respectable isolated yields under mild reaction conditions. The feasibility to perform the two-steps in
分为两步的方案,涉及在[BMIM] [PF 6 ]或[BMIM] [BF 4 ]中以Pd催化将易获得的对-溴苯基-醛亚胺环化为2-溴苯基-苯并恶唑/苯并噻唑,然后使用Suzuki,描述了由Pd或Ni催化的Heck和Sonogashira交叉偶联反应,可在温和的反应条件下以可观的分离产率生成不同取代的2-芳基-/杂芳基-苯并恶唑/苯并噻唑的文库。还显示了从醛亚胺开始在一锅中依次执行两个步骤的可行性,并且还显示了IL溶剂循环/再利用的潜力。