Broadly Applicable Z- and Diastereoselective Ring-Opening/Cross-Metathesis Catalyzed by a Dithiolate Ru Complex

• Published in: Angewandte Chemie (International ed.) Vol. 53; no. 7; pp. 1968 - 1972
• Main Authors: Koh, Ming Joo, Khan, R. Kashif M., Torker, Sebastian, Hoveyda, Amir H.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 10.02.2014; WILEY‐VCH Verlag; Wiley; Wiley Subscription Services, Inc
• Edition: International ed. in English
• Subjects: Alcohols; Alkenes; Chemistry; Chemistry, Multidisciplinary; Ethers; Hydrogen bonding; Ligands; olefin metathesis; Olefins; Physical Sciences; ring-opening/cross-metathesis; ruthenium; Science & Technology; synthetic methods; Terminals; Transformations; olefin metathesis; MO; ENOL ETHERS; MOLYBDENUM; OLEFIN CROSS-METATHESIS; REACTIVITY; RUTHENIUM CATALYSTS; alkenes; ring-opening; ruthenium; cross-metathesis; EFFICIENT; synthetic methods; ring-opening/cross-metathesis
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201309430

A broadly applicable Ru‐catalyzed protocol for Z‐selective ring‐opening/cross‐metathesis (ROCM) is disclosed. In addition to reactions relating to terminal alkenes of different sizes, the first examples of Z‐selective ROCM processes involving heteroaryl olefins, 1,3‐dienes, and O‐ and S‐substituted alkenes as well as allylic and homoallylic alcohols are reported. Z‐Selective transformations with an α‐substituted allylic alcohol are shown to afford congested Z alkenes with high diastereoselectivity. Transformations are performed in the presence of 2.0–5.0 mol % of a recently disclosed Ru‐based dithiolate complex that can be easily prepared in a single step from commercially available starting materials. Typically, transformations proceed at ambient temperature and are complete within eight hours; products are obtained in up to 97 % yield, >98:2 Z/E, and >98:2 diastereomeric ratio. The present investigations reveal a mechanistically significant attribute of the Ru‐based dithiolates that arises from electrostatic interactions with anionic S‐based ligands. Finally, the full range: For the first time, Ru‐catalyzed olefin metathesis transformations with heteroaryl‐substituted alkenes, 1,3‐dienes, enol ethers, and allylic and homoallylic alcohols can be performed efficiently and often with >98 % Z selectivity. Hydrogen bonding with the dithiolate ligand likely facilitates ring‐opening/cross‐metathesis reactions of allylic alcohols.