一种新的余2为苯并的C3-dicarbonylation [促进,高效金属和无过氧化物更环保的多米诺协议d ]咪唑并[2,1- b与苯乙烯]噻唑(IBTS)已经开发通过的氧化裂解C(sp 2)–H键,随后是IBT的C3亲核攻击和氧化。有趣的是,在这些条件下2-(苯并[ d ]咪唑并[ 2,1- b ]噻唑-2-基)苯胺得到苯并[4',5']噻唑并[2',3':2,3]咪唑[4,5- c ]喹啉衍生物通过C(sp 2的氧化裂解)–H键,然后进行Pictet–Spengler环化和芳构化。该方法除了具有更高的产率外,还具有广泛的底物范围,环保特性和高原子经济性的优点。
A convenient [hydroxy(tosyloxy)iodo]benzene-mediated one-pot synthesis of 2-arylimidazo[2,1-b]benzothiazoles
摘要:
Several 2-arylimidazo[2,1-b]benzothiazoles (4) have been conveniently synthesized in one-pot reactions via alpha-tosyloxylation of enolizable ketones (1) using [hydroxy(tosyloxy)iodo]benzene 2 in acetonitrile, followed by treatment with 2-amino-6-(substituted)benzothiazoles (3). The present protocol offers several advantages towards general access of 2-arylimidazo[2,1-b]benzothiazoles, including an intriguing alternative to the literature protocols, a readily available nontoxic reagent, operational simplicity and an environmentally benign procedure.
Iron-catalyzed unprecedented formation of benzo[d]imidazo[2,1-b]thiazoles under solvent-free conditions
作者:Sandip Gangadhar Balwe、Yeon Tae Jeong
DOI:10.1039/c6ra24183b
日期:——
unprecedented formation of benzo[d]imidazo[2,1-b]thiazole during iron-catalyzed coupling of 2-aminobenzothiazole, aldehydes with nitroalkane in air has been observed. This unique transformation possibly occurs through a sequential aza-Henry reaction and subsequent intramolecular cyclization, followed by denitration. A variety of substituted benzo[d]imidazo[2,1-b]thiazole are obtained using this protocol
观察到在空气中2-氨基苯并噻唑,醛与硝基烷的铁催化偶联过程中,苯并[ d ]咪唑并[ 2,1- b ]噻唑的空前形成。这种独特的转化可能是通过顺序的aza-Henry反应和随后的分子内环化,然后进行脱硝而发生的。使用该方案可获得各种取代的苯并[ d ]咪唑并[2,1- b ]噻唑。