Bulky Cyclometalated Ruthenium Nitrates for Challenging Z-Selective Metathesis: Efficient One-Step Access to α-Oxygenated Z-Olefins from Acrylates and Allyl Alcohols.

α-Oxygenated Z -olefins are ubiquitous in biologically active molecules and serve as versatile handles for organic synthesis, but their syntheses are often tedious and less selective. Here we report the efficient Z -selective metathesis of various terminal acrylates and allyl alcohols, which enables facile and selective construction of high value-added α-oxygenated Z -olefins from readily available feedstock chemicals. These challenging metathesis transformations are enabled by novel cyclometalated Ru-carbene-nitrate complexes bearing bulky-yet-flexible side arms, whose assembly was unlocked by new organometallic syntheses.