Preparation of Cyclophanes by Room-Temperature Ring-Closing Alkyne Metathesis with Imidazolin-2-iminato Tungsten Alkylidyne Complexes
作者:Stephan Beer、Kai Brandhorst、Jörg Grunenberg、Cristian G. Hrib、Peter G. Jones、Matthias Tamm
DOI:10.1021/ol800154y
日期:2008.3.1
Room-temperature ring-closing alkyne metathesis of 1,2-, 1,3-, and 1,4-bis(3-pentynyloxymethyl)benzenes has been investigated in the presence of catalytic amounts of an imidazolin-2-iminato tungsten alkylidyne complex. The m- and p-diynes selectively form the respective [10]metacyclophane or [10.10]paracyclophane, respectively, whereas a mixture of monomeric and dimeric cycloalkynes is obtained in