Affiliation:
1. Department of Chemistry City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong SAR
2. State Key Laboratory of Terahertz and Millimeter Waves City University of Hong Kong Tat Chee Avenue Kowloon Hong Kong SAR
3. School of Chemical Engineering and Light Industry Guangdong University of Technology GuangZhou P. R. China
Abstract
AbstractSystematic investigations on the reactions between cis‐[M(dppm)2Cl2] (M=Ru/Os; dppm=1,1‐bis(diphenylphosphino)methane) and pyridine/quinoline substituted homopropargylic alcohols uncovered the diverse Ru(II)/Os(II)‐induced alkyne activation pathways. The alkynes underwent cyclization on M via a “non‐vinylidene” pathway at lower temperatures, resulting in alkenyl intermediates which might further metallacyclize to give metallapyrroloindolizines. Conversely, reactions at higher temperatures induced alkyne cyclization on M via a “vinylidene” pathway, affording cyclic oxacarbene complexes. Additionally, a rare decyclization mechanism was observed during the transformation of a metallacyclization‐resistant alkenyl complex into a cyclic oxacarbene complex. DFT calculations were employed to validate the experimental findings. Overall, these results not only provide insights into controlling alkyne activation pathways, but also offer new strategies for preparing metalated heterocyclic and metallacyclic complexes.
Funder
University Research Committee, University of Hong Kong
Subject
General Chemistry,Catalysis,Organic Chemistry