A highly efficient TBAF-promoted intramolecular cyclization of gem-dibromoolefins for the synthesis of 2-bromobenzofurans(thiophenes)
作者:Wei Chen、Yicheng Zhang、Lei Zhang、Min Wang、Lei Wang
DOI:10.1039/c1cc13967c
日期:——
A highlyefficient tetra-(n-butyl)ammonium fluoride (TBAF)-promoted intramolecular cyclization of gem-dibromoolefins has been developed for the synthesis of 2-bromobenzofused heterocycles. The reaction provides a convenient approach to 2-bromobenzofurans(thiophenes) from the corresponding readily available gem-dibromovinyl substrates without a metal.
Intramolecular cross-coupling of gem-dibromoolefins: a mild approach to 2-bromo benzofused heterocycles
作者:Stephen G. Newman、Valentina Aureggi、Christopher S. Bryan、Mark Lautens
DOI:10.1039/b912093a
日期:——
Highly useful halogenated benzofurans and benzothiophenes are prepared from readily available gem-dibromoolefins using a mild, ligand-free copper catalyzed cross-coupling procedure.
Efficient Synthesis of Benzothiophenes by an Unusual Palladium-Catalyzed Vinylic CS Coupling
作者:Christopher S. Bryan、Julia A. Braunger、Mark Lautens
DOI:10.1002/anie.200902843
日期:2009.9.7
construction of a CS and a CC bond under catalytic conditions forms the basis of an efficient route to diversely functionalized benzothiophenes from gem‐dihalovinyl thiophenols. The CC bond can be formed in this tandem catalytic process with an organoboron reagent as shown in the scheme (R1=H, Me, F, Cl, Br, OCH2O; R2=H, Me; R3=aryl, heteroaryl, alkenyl, alkyl), or by Heck or Sonogashira coupling with an
同时施工一个C S和一个C 催化条件下C键形成从不同地官能化的苯并噻吩的高效路由的基础宝石-dihalovinyl苯硫酚。与c 可以在此串联与有机硼试剂催化工艺来形成C键为显示在方案(R 1 = H中,Me,F,氯,溴, OCH 2 ö ; R 2 = H中,Me; R 3=芳基,杂芳基,烯基,烷基),或通过Heck或Sonogashira与烯烃或炔烃偶联。
Trace amount Cu (ppm)-catalyzed intramolecular cyclization of 2-(gem-dibromovinyl)phenols(thiophenols) to 2-bromobenzofurans(thiophenes)
作者:Yong Ji、Pinhua Li、Xiuli Zhang、Lei Wang
DOI:10.1039/c3ob40531a
日期:——
An intramolecular cyclization of 2-(gem-dibromovinyl)phenols(thiophenols) to give 2-bromobenzofurans(thiophenes) in the presence of a trace amount of Cu (0.0064 mol%, 25 ppm) has been developed. The reaction provides the desired products in excellent yields under fluoride-free and mild reaction conditions and with a TON (turnover number) of up to 1.5 × 104.