Synthesis of Ruthenium Hydride Complexes Supported by Bidentate NHC–Indolide Ligands and Their Catalytic Activity in H/D Exchange Reactions of Olefins with D ₂ O

High Resolution Image Download MS PowerPoint Slide Two new ruthenium hydride complexes supported by monoanionic NHC–indolide (LX-type) ligands have been synthesized and fully characterized. The resulting ruthenium hydrides exhibit catalytic activity in H/D exchange reactions between olefins and D 2 O and tolerate multiple functional groups, including halides, ethers, esters, alcohols, and amines. Notably, the catalysts promote preferential deuteration at C═C bonds of monosubstituted olefins (RCH = CH 2 ) relative to 1,2-disubstituted and trisubstituted olefins. The catalytic reactions involve H/D exchange between the Ru–H bond and D 2 O, as well as reversible olefin insertion into Ru–D(H). The isolation of an insertion product from the reaction with 2-vinylpyridine provides direct experimental support for this mechanistic proposal.