52939-90-9Relevant academic research and scientific papers
Asymmetric Aza-Diels-Alder Reactions of in Situ Generated β,β-Disubstituted α,β-Unsaturated N-H Ketimines Catalyzed by Chiral Phosphoric Acids
He, Shunlong,Gu, Huanchao,He, Yu-Peng,Yang, Xiaoyu
supporting information, p. 5633 - 5639 (2020/07/14)
A novel asymmetric synthesis of dihydropyridinones with vicinal quaternary stereocenters has been realized by asymmetric aza-Diels-Alder reactions of 3-amido allylic alcohols with oxazolones enabled by chiral phosphoric acid catalysis. A series of aryl/alkyl- and alkyl/alkyl-disubstituted 3-amido allylic tertiary alcohols and 4-substituted oxazolones could be well tolerated in these reactions, producing dihydropyridinones with excellent diastereoselectivities and high enantioselectivities. Mechanistic study and control experiments were performed to shed light on the reaction mechanism, in which a configurationally defined β,β-disubstituted α,β-unsaturated N-H ketimine was proposed as the key intermediate.
Electrochemical synthesis of enaminones: Via a decarboxylative coupling reaction
Kong, Xianqiang,Liu, Yulong,Lin, Long,Chen, Qianjin,Xu, Bo
supporting information, p. 3796 - 3801 (2019/07/31)
An environmentally benign and efficient electrochemical synthesis of enaminones via a decarboxylative coupling reaction of α-keto acids using n-Bu4NI as a redox catalyst and electrolyte under constant current electrolysis in an undivided cell is reported. A broad vinyl azide substrate scope and high functional group tolerance are observed. A gram-scale reaction further demonstrates the practicability of the protocol. The results of cyclic voltammetry and control experiments indicate that I2 is likely the active species to initiate the oxidative decarboxylation via an acyl hypoiodite intermediate.
Metal-Free Method for Direct Synthesis of Functionalized β-Ketoenamines
Zeng, Xiaobao,Liu, Chulong,Yang, Weiguang,Weng, Yunxiang,Wang, Xinyan,Hu, Yuefei
, p. 3656 - 3661 (2019/03/20)
A new method for direct synthesis of β-ketoenamines was developed by a BF3·OEt2-catalyzed cyclization of 1-iodoalkyne and α-keto acid followed by an amine-mediated ring-opening in one pot. Its metal-free conditions allowed the easy synthesis of those products bearing the transition metal-sensitive functional groups. Its three-component process achieved wide range of functionalized products.
Radical Enamination of Vinyl Azides: Direct Synthesis of N-Unprotected Enamines
Ning, Yongquan,Zhao, Xue-Feng,Wu, Yan-Bo,Bi, Xihe
supporting information, p. 6240 - 6243 (2017/11/24)
An electron-withdrawing-group-generable radical-induced enamination of vinyl azides is reported, which results in a variety of β-functionalized N-unprotected enamines in a stereoselective manner. A plausible mechanism involving an unusual 1,3-H transfer of in situ generated iminyl radical intermediate was proposed on the basis of experimental results and DFT calculations.
Synthesis of enaminones via copper-catalyzed decarboxylative coupling reaction under redox-neutral conditions
Zhu, Zhongzhi,Tang, Xiaodong,Li, Jianxiao,Li, Xianwei,Wu, Wanqing,Deng, Guohua,Jiang, Huanfeng
, p. 3228 - 3231 (2017/03/20)
A novel copper-catalyzed C(sp3)-H oxidative functionalization of aromatic oxime acetates with α-oxocarboxylic acids was reported. This process involved N-O/C-C bond cleavages and C-C bond formations to furnish substituted enaminones under redox-neutral conditions. The oxime acetates served as both reactants and internal oxidants. Furthermore, this transformation also features good functional group tolerance and needs no ligands or additional bases.
Copper-catalyzed aldol-type addition of ketones to aromatic nitriles: A simple approach to enaminone synthesis
Yu, Xiaoqiang,Wang, Longxiang,Feng, Xiujuan,Bao, Ming,Yamamoto, Yoshinori
supporting information, p. 2885 - 2887 (2013/04/24)
An efficient method for the synthesis of enaminones is described. The aldol-type addition of ketones to aromatic nitriles proceeded smoothly in the presence of a simple copper catalyst system (CuI-2,2′-bipyridine-NaO tBu) in N,N-dimethylformamide. Enaminones in satisfactory to excellent yields were produced using this technique. The Royal Society of Chemistry 2013.
Solid-state synthesis of β-enamino ketones from solid 1,3-dicarbonyl compounds and ammonium salts or amines
Xu, Shi-Liang,Li, Cheng-Ping,Li, Jing-Hua
experimental part, p. 818 - 822 (2009/07/18)
A facile amination of solid 1,3-dicarbonyl compounds with ammonium salts or amines in solid state has been achieved by mechanochemical grinding in the presence of KHSO4 and SiO2. Most of the reactions proceed smoothly at room temperature under solid-state conditions and give their corresponding β-imino derivatives in high yields. The method has the advantage of simple manipulation and mild conditions. Georg Thieme Verlag Stuttgart.
