一种新颖的铑催化3-取代的吲哚与重氮烯的吡啶鎓吡啶环反应,并提供了优先的吡啶并[1,2- a ]吲哚。提出该反应涉及通过吲哚的C-2官能化使二受体铑烯醛烯类化合物[4 + 2]环化。该方法的实用性通过四氢吡啶并[1,2- a ]吲哚核的短合成得到证明,该四氢吡啶并[1,2- a ]吲哚核存在于大量生物学上重要的多环吲哚生物碱中。
Metal-free and regiospecific synthesis of 3-arylindoles
作者:Chuangchuang Xu、Wenlai Xie、Jiaxi Xu
DOI:10.1039/d0ob00317d
日期:——
arylhydrazine hydrochlorides and Fischer indolization. The organic base triethylamine plays a crucial role in the final elimination step in the Fischer indole synthesis, affording 3-arylindoles regiospecifically. The reaction features advantages of microwave acceleration, non-metal participation, short reaction time, organic acid-base co-catalysis, and broad substrate scope.
“On Water” Direct and Site-Selective Pd-Catalysed CH Arylation of (NH)-Indoles
作者:Lionel Joucla、Nelly Batail、Laurent Djakovitch
DOI:10.1002/adsc.201000512
日期:2010.11.22
communication describes the development of a versatile catalytic system based on palladium(II) acetate/bis(diphenylphosphino)methane [Pd(OAc)2/dppm] that works “on water” giving site-selective CH arylation of (NH)-indoles without protecting or directing groups. Remarkably, the control of regioselectivity was achieved by small changes in the “extra-catalytic” base/halide partners. These innovative methodologies
Pyridylmethylamine-Palladium Catalytic Systems: A Selective Alternative in the C−H Arylation of Indole
作者:Serge Perato、Benjamin Large、Qiao Lu、Anne Gaucher、Damien Prim
DOI:10.1002/cctc.201601275
日期:2017.2.6
A highly efficient pyridylmethylamine‐Pd alternative catalytic system for the C−H arylation of indole was explored. Variously substituted aryl groups were regio‐ and chemoselectively installed at the indole nucleus by using barium hydroxide as the base. The method was found to be efficient even in the presence of hindered coupling partners and Pd‐reactive bonds.
A novel palladium‐catalyzed approach to direct C‐3‐arylation of 1H‐indoles with arylhydrazines using air as the oxidant viaCN bond cleavage has been developed. Various substituents are tolerated in this system in moderate to good yields. This reaction could also be compatible with a larger scale. Thus, this strategy using arylhydrazines as arylating reagents provides a powerful method for constructing
catalyst–base pair for the C–H arylation of free (NH)-indoles in the C-3 position is reported. Ligand-free palladium acetate coupled with lithium hexamethyldisilazide (LiHMDS) catalyzed the regiospecific, i.e. 100% regioselective, C-3 arylation of indoles with high turnover numbers. This catalytic system has been successfully applied to a wide range of substrates, including various functional arylhalides and