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

摘要

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 a-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.