Syntheses of Seven-Membered Rings: Ruthenium-Catalyzed Intramolecular [5+2] Cycloadditions
作者:Barry M. Trost、Hong C. Shen、Daniel B. Horne、F. Dean Toste、Bernhard G. Steinmetz、Christopher Koradin
DOI:10.1002/chem.200401065
日期:2005.4.8
The Ru-catalyzed intramolecular [5+2] cycloaddition of cyclopropylenynes is investigated with respect to the regio- and diastereoselectivity as well as the functional group compatibility of the reaction. Evidence for the mechanism as occurring through a ruthenacyclopentene intermediate is elucidated from 1) the study of the diastereoselectivity of the cycloaddition; 2) the effect of variation of substituents
关于区域和非对映体选择性以及反应的官能团相容性,研究了Ru催化的环丙炔的分子内[5 + 2]环加成反应。通过1)环加成的非对映选择性的研究阐明了通过钌烷基环戊烯中间体发生这种机理的证据。2)取代基变化对1,2-反式和1,2-顺式二取代的环丙烷中环丙基键断裂的区域选择性的影响,以及3)显然不涉及钌环戊己烯作为中间体的实例,因为产物仍包含环丙基部分。讨论了Ru催化的环加成反应的范围和局限性,并与Rh催化的反应进行了比较。