Rh-Catalyzed Enantioselective [2 + 2] Cycloaddition of Alkynyl Esters and Norbornene Derivatives
作者:Takanori Shibata、Kyoko Takami、Ai Kawachi
DOI:10.1021/ol060055r
日期:2006.3.1
[reaction: see text] The enantioselective [2 + 2] cycloaddition of alkynes possessing an ester functionality and norbornene derivatives proceeded efficiently using a chiral rhodium catalyst. The chiral tri- and tetracyclic cyclobutenes were obtained in moderate to high ee.
Rhenium-catalyzed [2+2] Cycloadditions of Norbornenes with Internal and Terminal Acetylenes
作者:Yoichiro Kuninobu、Peng Yu、Kazuhiko Takai
DOI:10.1246/cl.2007.1162
日期:2007.9.5
Treatment of norbornenes with internal and terminal acetylenes in the presence of a catalytic amount of [ReBr(CO)3(thf)]2 gave cyclobutene derivatives in good to excellent yields.