Yu Robert T, Rovis Tomislav
Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, USA.
J Am Chem Soc. 2006 Sep 27;128(38):12370-1. doi: 10.1021/ja064868m.
The use of TADDOL-based phosphoramidite ligands on rhodium allows for the incorporation of terminal alkynes in the [2+2+2] cycloaddition with alkenyl isocyanates. Terminal aliphatic alkynes provide bicyclic lactams, while the use of aryl alkynes provides complementary access to vinylogous amides. Product selectivity seems to be governed by a combination of electronics and sterics, with smaller and/or more electron-deficient substituents favoring lactam formation. The use of homologous alkenyl isocyanates leads to an expedient asymmetric total synthesis of the alkaloid lasubine II.
基于TADDOL的亚磷酰胺配体在铑上的应用，使得末端炔烃能够与烯基异氰酸酯进行[2+2+2]环加成反应。末端脂肪族炔烃生成双环内酰胺，而芳基炔烃的使用则为合成烯醇酰胺提供了互补的方法。产物的选择性似乎受电子效应和空间效应共同影响，较小和/或电子缺乏程度较高的取代基有利于内酰胺的形成。使用同系烯基异氰酸酯可实现生物碱拉苏宾II的便捷不对称全合成。
