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
Pd/β-cyclodextrin-catalyzed C–H functionalization in water: a greener approach to regioselective arylation of (NH)-indoles with aryl bromides
作者:Peng Xu、Xin Hong Duan
DOI:10.1039/d1nj03400f
日期:——
A greener and more practical strategy for the site-selective C–H arylation of (NH)-indoles via coupling of (hetero)aryl bromides was developed, in which β-cyclodextrin, acting as both a ligand for Na2PdCl4 and a host for indoles, enables the reactions to occur easily in water. The key advantage of this method is the ingenious merging of aqueous homogeneous catalysis and ligand mediation, leading to
开发了一种更环保、更实用的策略,用于通过(杂)芳基溴化物的偶联对 (NH)-吲哚进行位点选择性 C-H 芳基化,其中 β-环糊精作为 Na 2 PdCl 4的配体和吲哚的宿主,使反应在水中容易发生。这种方法的关键优势是水相均相催化和配体介导的巧妙融合,导致具有广泛底物范围和官能团耐受性的 C3-芳基吲哚的高度区域选择性形成。此外,区域选择性可以通过改变碱基的性质而从 C3 位切换到 C2 位,而无需使用 ArI 作为底物。
Palladium-Catalyzed Direct Denitrogenative C-3-Arylation of 1<i>H</i>-Indoles with Arylhydrazines using Air as the Oxidant
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