3548-71-8Relevant academic research and scientific papers
Lewis Acid-Catalyzed Nucleophilic Addition of Indoles to in Situ-Generated 2-Amidoallyl Cations
Schlegel, Marcel,Schneider, Christoph
, p. 5986 - 5992 (2017)
We report herein the first Lewis acid-catalyzed generation of 2-amidoallyl cations through ring-opening of 4-benzylidene-2-oxazolines with Sc(OTf)3. Upon nucleophilic addition of indoles, indolylenamides were obtained with yields of 60-99% and excellent (Z)-selectivity. In addition, the novel strategy was also successfully applied to pyrroles and naphthols as -nucleophiles. A Br?nsted acid-catalyzed process using TfOH formed in situ was ruled out by control experiments.
Chemo- and Enantioselective Hydrogenation of α-Formyl Enamides: An Efficient Access to Chiral α-Amido Aldehydes
Zhang, Jian,Jia, Jia,Zeng, Xincheng,Wang, Yuanhao,Zhang, Zhenfeng,Gridnev, Ilya D.,Zhang, Wanbin
supporting information, p. 11505 - 11512 (2019/07/17)
In order to effectively synthesize chiral α-amino aldehydes, which have a wide range of potential applications in organic synthesis and medicinal chemistry, a highly chemo- and enantioselective hydrogenation of α-formyl enamides has been developed, catalyzed by a rhodium complex of a P-stereogenic bisphosphine ligand. Under different hydrogen pressures, the chiral α-amido aldehydes and β-amido alcohols were obtained in high yields (97–99 %) and with excellent chemo- and enantioselectivities (up to >99.9 % ee). The hydrogenation can be carried out on a gram scale and with a high substrate/catalyst ratio (up to 20 000 S/C), and the hydrogenated products were further converted into several important chiral products. Computations of the catalytic cycle gave a clear description for the R/S pathways, provided a reasonable explanation for the enantioselectivity, and revealed several other specific features.
Physical characteristics and polarographic reduction mechanism of some oxazolones
Ismail, M. I.
, p. 1886 - 1892 (2007/10/02)
The redox potential (ΔE1/2), electron affinity (EA), ionization potential (IP), coulomb repulsion integral (J12), and electronic transition energy (ECT) of several oxazolone derivatives in DMF were computed.A linear correlation was shown to exist between ΔE1/2 and ECT.The polarographic reduction was investigated in ethanolic-Theil buffer solutions.At pH /= 7.2, two waves were obtained representing the uptake of 2- and 4-electron steps respectively.In alkaline media, a third wave appeared seemingly a result of the hydrolysis of oxazolones.The rate of hydrolysis was determined and the electrode mechanism was elucidated and confirmed via spectrophotometric and coulometric analysis. Key words: oxazolones, polarography, electrochemistry, electrode reaction, spectrophotometry, redox potential.
