As strong as an aux: An electronically‐tuned hydroxylamine functions as an excellent chiral auxiliary for [3+2] cycloaddition of the azomethineylidesgenerated in‐situ from gold‐catalyzed redox reaction of alkynyl nitrones.
Gold-Catalyzed Waste-Free Generation and Reaction of Azomethine Ylides: Internal Redox/Dipolar Cycloaddition Cascade
作者:Hyun-Suk Yeom、Ji-Eun Lee、Seunghoon Shin
DOI:10.1002/anie.200802802
日期:2008.9.1
Synthesis of Colchicinoids and Allocolchicinoids through Rh(I)-Catalyzed [2+2+2+1] and [2+2+2] Cycloadditions of <i>o</i>-Phenylenetriynes with and without CO
作者:Chih-Wei Chien、Yu-Han Gary Teng、Tadashi Honda、Iwao Ojima
DOI:10.1021/acs.joc.8b01608
日期:2018.10.5
carbonylative [2+2+2+1] cycloaddition of triynes to the formation of a fused tropone system, we report here the application of this methodology to the one-step formation of the 6–7–7–5 fused tetracyclic scaffold of colchicinoids based on the [2+2+2+1] cycloaddition of o-phenylenetriynes with CO. In addition, the one-step formation of allocolchicinoids bearing the 6–7–6–5 fused tetracyclic system through the Rh-catalyzed