5553-90-2Relevant academic research and scientific papers
Catalyst-Free [3 + 3] Annulation/Oxidation of Cyclic Amidines with Activated Olefins: When the Substrate Olefin Is Also an Oxidant
Han, Wendan,Li, Yuanhang,Raveendra Babu, Kaki,Li, Jing,Tang, Yuhai,Wu, Yong,Xu, Silong
, p. 7832 - 7841 (2021/06/25)
Herein we describe a catalyst-free regioselective [3 + 3] annulation/oxidation reaction of cyclic amidines such as DBU (1,8-diazabicyclo(5.4.0)undec-7-ene) and DBN (1,5-diazabicyclo(4.3.0)non-5-ene) with activated olefins, i.e., 2-arylidenemalononitriles and 2-cyano-3-aryl acrylates, to afford tricyclic 2-pyridones and pyridin-2(1H)-imines, respectively. The mechanism has been proposed based on DFT calculations. In the reaction, the cyclic amidines serve as C,N-bisnucleophiles for the cyclization, while the olefins play a dual role by acting as both reactants and oxidants.
Base-Promoted Cascade Approach for the Preparation of Reduced Knoevenagel Adducts Using Hantzsch Esters as Reducing Agent in Water
He, Tao,Shi, Ronghua,Gong, Yimou,Jiang, Guangyou,Liu, Ming,Qian, Shan,Wang, Zhouyu
supporting information, p. 1864 - 1869 (2016/07/16)
A cascade Knoevenagel condensation-reduction approach, which was carried out in water, has been reported. Using Hantzsch esters as reducing agent, under the promotion of base, a variety of reduced Knoevenagel adducts could be easily prepared by direct alkylation of malononitrile, ethyl 2-cyanoacetate, and 2-(4-nitrophenyl)acetonitrile, respectively. Meanwhile, a gram-scale synthesis of the protocol was also realized with excellent isolated yield.
Catalyst-free chemoselective reduction of the carbon-carbon double bond in conjugated alkenes with Hantzsch esters in water
He, Qi,Xu, Zhihong,Jiang, Dehong,Ai, Wensi,Shi, Ronghua,Qian, Shan,Wang, Zhouyu
, p. 8671 - 8674 (2014/03/21)
A simple, efficient and green protocol for chemoselective reduction of carbon-carbon double bond in conjugated alkenes with Hantzsch esters is described. Without any additional catalysts, a series of conjugated alkenes with strong electron-withdrawing groups were reduced in water with excellent yield. Functional groups such as nitrile, ester, nitro, fluoro, chloro, bromo, furanyl and benzyl are all tolerated by the reaction conditions employed. The Royal Society of Chemistry.
