Facile palladium-catalysed synthesis of 1-aryl-1H-indazoles from 2-bromobenzaldehydes and arylhydrazines
作者:Chan Sik Cho、Dong Kwon Lim、Nam Ho Heo、Tae-Jeong Kim、Sang Chul Shim
DOI:10.1039/b312154m
日期:——
2-Bromobenzaldehydes react with arylhydrazines in toluene at 100 [degree]C in the presence of a catalytic amount of a palladium catalyst and phosphorus chelating ligands such as 1,1[prime or minute]-bis(diphenylphosphino)ferrocene and 1,3-bis(diphenylphosphino)propane along with NaO-t-Bu to afford 1-aryl-1H-indazoles in good yields.
Efficient Synthesis of 1‐Aryl‐1<i>H</i>‐indazole Derivatives via Copper(I)‐Catalyzed Intramolecular Amination Reaction
作者:Rui Liu、Yongming Zhu、Liena Qin、Shunjun Ji
DOI:10.1080/00397910701750250
日期:2008.1
Abstract A copper(I)‐catalyzed intramolecularamination reaction using CuI, KOH, and 1,4‐dioxane at 105°C for the preparation of 1‐aryl‐1H‐indazole derivatives was described. The method was applied to a wide scope of substrates and afforded indazole products in high yields.
Regiodivergent Cu-Promoted, AcOH-Switchable Distal Versus Proximal Direct Cyanation of 1-Aryl-1<i>H</i>-indazoles and 2-Aryl-2<i>H</i>-indazoles via Aerobic Oxidative C–H Bond Activation
作者:Richa Sharma、Sandeep Chaudhary
DOI:10.1021/acs.joc.2c01603
日期:2022.12.16
A copper-promoted regiodivergent, AcOH-switchable, distal and proximal direct cyanation of N-aryl-(1H/2H)-indazoles via aerobic oxidative C(sp2)–H bondactivation has been developed. The inclusion or exclusion of AcOH as an additive is the foremost cause for the positional switch in the C–CN bond formation method that results in (C-2′)-cyanated 2-aryl-2H-indazoles 3a–j, (C-2′)-cyanated 1-aryl-1H-indazoles
开发了一种通过有氧氧化 C(sp 2 )–H 键激活对N -芳基-(1 H /2 H )-吲唑进行铜促进区域发散、AcOH 可切换、远端和近端直接氰化反应。添加或排除 AcOH 作为添加剂是导致 (C-2')-氰化 2-芳基-2 H-吲唑3a-j的 C-CN 键形成方法中位置转换的主要原因,(C -2')-cyanated 1-aryl-1 H -indazoles 4a–j [distal], 或 C-3 cyanated 2-aryl-2 H -indazoles 5a–i [proximal] 产品具有良好至优异的产率并显示出各种功能群体耐受性。氰化物(CN– ) 离子替代物是通过二甲基甲酰胺和碘化铵 (NH 4 I) 的统一生成的。使用分子氧(有氧氧化策略)作为一种清洁安全的氧化剂可以带来大量的附加值。通过将合成的氰化产物转化为许多其他官能团,证明了所开发协议的进一步针对性,这无疑
Synthesis of 1-aryl-1 H -indazoles via the palladium-catalyzed cyclization of N -aryl- N ′-( o -bromobenzyl)hydrazines and [ N -aryl- N ′-( o -bromobenzyl)-hydrazinato- N ′]-triphenylphosphonium bromides
作者:Jinhua J Song、Nathan K Yee
DOI:10.1016/s0040-4039(01)00273-8
日期:2001.4
1-Aryl-1H-indazoles were synthesized by the palladium-catalyzed intramolecular amination [Pd(OAc)2/dppf/tBuONa (150 mol%)/toluene/90°C] of the corresponding N-aryl-N′-(o-bromobenzyl)hydrazines. It was further demonstrated that cyclization of [N-aryl-N′-(o-bromobenzyl)-hydrazinato-N′]-triphenylphosphonium bromides under the conditions of [Pd(OAc)2/dppf/tBuONa (250 mol%)/dioxane/90°C] also led to the