已成功描述了N-杂芳基芳烃与炔烃的机械化学、无溶剂 Ru(II) 催化的烯基化反应。具有N-杂芳基部分的广谱芳烃,例如咪唑并[1,2- a ]吡啶、咪唑并[1,2- a ]嘧啶、苯并[ d ]咪唑并[2,1- b ]噻唑、咪唑[2, 1 - b ]噻唑、2H-吲唑、1H-吲唑、1H-吡唑和1,2,4-恶二唑-5( 4H )-one作为导向基团在球磨下与各种取代的炔烃反应[Ru( p -cymene)Cl 2 ] 2的存在,以中等至良好的产率提供二烯基化产物。2,3-dihydrophthalazine-1,4-dione 与 1-phenyl-1-propyne 反应得到单烯基化产物。类似地,2-苯基咪唑并[1,2- a ]吡啶与脂肪族末端炔烃的反应产生了作为主要产物的单烯基化衍生物以及少量的二烯基化产物。所开发的方法表现出优异的官能团相容性、广泛的底物范围、较短的反应时间和无需外部加热。此外,该方法可以很容易地按比例放大,如
Selective Synthesis of Indazolo[2,3‐
<i>a</i>
]quinolines via Rh(III)‐Catalyzed Oxidant‐Free [4+2] or [5+1] Annulation of 2‐Aryl‐2
<i>H</i>
‐indazoles with
<i>α</i>
‐Diazo Carbonyl Compounds
作者:Shenghai Guo、Lincong Sun、Xuzhuo Li、Xinying Zhang、Xuesen Fan
DOI:10.1002/adsc.201901422
日期:2020.2.21
A selective synthesis of 5,6‐disubstituted and 5‐substituted indazolo[2,3‐a]quinolines through a Rh(III)‐catalyzed oxidant‐free annulation of 2‐aryl‐2H‐indazoles with α‐diazo carbonyl compounds is reported. With 2‐aryl‐2H‐indazoles as the substrates, α‐diazo carbonyl compounds could act as a C2 synthon to afford 5,6‐disubstituted indazolo[2,3‐a]quinolines via a Rh(III)‐catalyzed [4+2] annulation. On
通过Rh(III)催化的2-芳基-2 H-吲唑与α-重氮羰基化合物的无氧化剂环氧化反应选择性合成5,6-二取代和5-取代的吲唑并[2,3- a ]喹啉是报告。以2-芳基-2 H-吲唑为底物,α-重氮羰基化合物可作为C2合成子,通过Rh(III)催化[ 5,6-二取代的吲唑并[2,3- a ]喹啉] [4 +2]。另一方面,当使用2-芳基-3-甲酰基-2 H-吲唑类作为底物时,α-重氮羰基化合物转变为C1合成子,需要经历更复杂的[5 + 1]环化工艺来提供5位取代的吲哚并[2,3- a ]喹啉。
Electrochemical Radical–Radical Cross-Coupling Approach between Sodium Sulfinates and 2<i>H</i>-Indazoles to 3-Sulfonylated 2<i>H</i>-Indazoles
作者:Wansoo Kim、Hun Young Kim、Kyungsoo Oh
DOI:10.1021/acs.orglett.0c02144
日期:2020.8.21
A direct cross-coupling between sodium sulfinates and 2H-indazoles has been developed under electrochemical conditions. The utilization of a graphite anode and platinum cathode in an undivided cell with a constant current of 7 mA allowed the concurrent oxidations of sulfinates and 2H-indazoles to sulfonyl radical and radical cationic 2H-indazoles, facilitating the direct radical–radical coupling strategy
Direct Acyl Radical Addition to 2<i>H</i>-Indazoles Using Ag-Catalyzed Decarboxylative Cross-Coupling of α-Keto Acids
作者:Ganganna Bogonda、Hun Young Kim、Kyungsoo Oh
DOI:10.1021/acs.orglett.8b00920
日期:2018.5.4
A direct acyl radical addition to 2H-indazoles has been achieved for the first time, where the less-aromatic quinonoid 2H-indazoles readily accepted radical species to the C-3 position. Motivated by the lack of direct acylation strategy for 2H-indazoles, the current method utilizes the radical acceptability of 2H-indazoles, discovering an ambient temperature reaction to provide facile access to a diverse
A straightforward and efficient method for the preparation of 2-aryl-2H-indazoles from ortho-alkyl substituted azoxybenzenes is presented. The reaction proceeds through base-catalyzed benzyl C–H deprotonation and cyclization to afford 2-aryl-2H-indazoles in good yields. This synthetic strategy can be applied to the construction of several fluorescent and bioactive molecules.
methods for one-pot transformations are highly challenging in synthetic organic chemistry. In this study, the Cu2Orhombic dodecahedra-catalyzed synthesis of 2H-indazoles is demonstrated with good to excellent yields from readily available chemicals. This one-pot procedure involves Cu2O nanoparticle-catalyzed consecutive C-N, and N-N bond formation followed by cyclization to yield 2H-indazoles with