Ruthenium‐Triggered Ring Opening of Ethynylcyclopropanes: [3+2] Cycloaddition with Aldehydes and Aldimines Involving Metal Allenylidene Intermediates

It's complex: Ruthenium-catalyzed [3+2] cycloaddition of ethynylcyclopropanes with aldehydes and aldimines has been found to give the corresponding 2-ethynyltetrahydrofurans or -pyrrolidines in high to excellent yields. In both cases, the formation of a ruthenium allenylidene complex as a key reactive intermediate is supported by density functional theory calculations. Cp*=η5-C5Me5. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.