Chiral Pincer Ligands
Metal-catalyzed olefin hydroarylation is an important, atom economical C–C bond-forming strategy for the synthesis of functionalized arenes. Of particular significance is the development of chiral catalysts that render this process enantioselective. Enantioselective olefin hydroarylation methods are scarce, and are generally limited to intramolecular variants or electron deficient alkenes.
In work published in JACS, researchers in the Meek Group report catalytic enantioselective addition of N-heteroarenes to terminal and internal 1,3-dienes.
Reactions are promoted by 5 mol % of Rh catalyst supported by a new chiral pincer carbodicarbene ligand that delivers allylic substituted arenes in up to 95% yield and up to 98:2 er. Mechanistic and X-ray evidence is presented that supports that the reaction proceeds via a Rh(III)-η3-allyl.