Efficient and Mild Ullmann-Type N-Arylation of Amides, Carbamates, and Azoles in Water
作者:Maud Bollenbach、Pedro G. V. Aquino、João Xavier de Araújo-Júnior、Jean-Jacques Bourguignon、Frédéric Bihel、Christophe Salomé、Patrick Wagner、Martine Schmitt
DOI:10.1002/chem.201700832
日期:2017.10.4
A simple, sustainable, efficient, mild, and low‐cost protocol was developed for d‐glucose‐assisted Cu‐catalyzed Ullmann reactions in water for amides, carbamates, and nitrogen‐containing heterocycles. The reaction was compatible with diverse aryl/heteroaryl iodides, giving highly substituted pyridine, indole, or indazole rings. This method offers an attractive alternative to existing protocols, because
A simple and direct approach for the regioselective construction of the privileged 2H‐indazole scaffold is described. The developed one‐pot strategy involves phospholene‐mediated N−N bond formation to access 2H‐indazoles. The amount of organophosphorus reagent was minimized by recycling the phospholene oxide with organosilane reductants. Starting from functionalized 2‐nitrobenzaldehydes and primary
direct synthesis of 3-substituted-2H-indazole derivatives was developed in the presence of AgNO3/Na2S2O8 under mild reaction conditions. The reaction affords a series of 1,3-dicarbonyl-2H-indazoles products with yields of up to 82%. The mechanism of the strategy suggests that the reaction proceeds through a radical pathway. Moreover, this strategy provides a new protocol for the synthesis of functionalized
在温和的反应条件下,在 AgNO 3 /Na 2 S 2 O 8存在下,开发了一种直接合成 3-取代-2 H-吲唑衍生物的便捷策略。该反应提供了一系列 1,3-二羰基-2 H-吲唑产物,产率高达 82%。该策略的机制表明反应通过自由基途径进行。此外,该策略为功能化 2 H-吲唑的合成提供了新的方案。
Electrochemically mediated trifluoromethylation of 2H-indazole derivatives using CF3SO2Na
An environmentally friendly method of electrochemical mediated regioselectiveC-3 trifluoromethylation of 2H-indazole by employing CF3SO2Na as the CF3 source was described. This reaction tolerated various functional groups and provided CH trifluoromethylated products in moderate to good yields under transitionmetal-free and oxidant-free reaction conditions. Mechanism experiments showed that a radical
描述了一种以 CF 3 SO 2 Na 作为 CF 3源的电化学介导的 2H-吲唑区域选择性 C-3 三氟甲基化的环境友好方法。该反应耐受各种官能团,并在无过渡金属和无氧化剂的反应条件下以中等至良好的产率提供 C H 三氟甲基化产物。机理实验表明,这种转变可能涉及一个激进的过程。
Rhodium(<scp>iii</scp>)-catalyzed <i>ortho</i>-C–H amidation of 2-arylindazoles with a dioxazolone as an amidating reagent
has been established for the first time through a rhodium-catalyzed C-H activation reaction with alkyl, aryl and heteroaryl dioxazolones. A series of N-(2-(2H-indazol-2-yl)phenyl)acetamide derivatives were synthesized in excellent yields. A mechanistic study was conducted to describe C-H bondcleavage which is likely to be involved in the rate determining step.