Remarkable Reactivity Difference in Oxygen-Substituted versus Non-Oxygen-Substituted Bromoalkynes in Cu(I)-Catalyzed Cross-Coupling Reactions: Total Synthesis of (−)-<i>S</i>-18-Hydroxyminquartynoic Acid
作者:Benjamin W. Gung、Godwin Kumi
DOI:10.1021/jo0344900
日期:2003.7.1
three-component Cadiot-Chodkiewicz reaction affording the tetrayne unit. The oxygen-substituted bromoalkyne 10 was found to react at a much faster rate than the non-oxygen-substituted bromoalkyne 6 in the key step. The undesired symmetric cross-coupling by 10 generates a symmetric tetrayne intermediate, which undergoes a nucleophilic addition by 1 equiv of ethylamine. This side reaction is suppressed by controlling