Catalytic Asymmetric Cycloaddition Reaction of Alkenyl Trichloroacetates with Nitrones
作者:Akira Yanagisawa、Atsuto Izumiseki、Takuya Sugita、Naoyuki Kushihara、Kazuhiro Yoshida
DOI:10.1055/s-0031-1290094
日期:2012.1
(S)-BINOL-derived chiral tindibromide possessing a 4-trifluoromethylphenyl group at 3- and 3′-positions as the chiral precatalyst in the presence of sodium ethoxide, sodium iodide, and ethanol. Optically active isoxazolidines with up to 95% ee were diastereoselectively obtained in high yields even from aliphatic aldehyde derived nitrones under the influence of the in situ generated chiral tin ethoxide iodide
Silver‐Catalyzed [3+1+1] Annulation of Nitrones with Isocyanoacetates as an Approach to 1,4,5‐Trisubstituted Imidazoles
作者:Lanlan Lv、Yan Chen、Andrey Shatskiy、Jian‐Quan Liu、Xiaoyi Liu、Markus D. Kärkäs、Xiang‐Shan Wang
DOI:10.1002/ejoc.202001536
日期:2021.2.12
A silver‐catalyzed protocol for [3+1+1] annulation of nitrones and isocyanoacetates is reported. The reaction is proposed to proceed through sequential [3+2] cycloaddition, ring‐opening, cyclization‐oxidation, and dealkylation, allowing access to a broad scope of valuable polysubstituted imidazoles in high yields.