If you are looking for high-quality products, please feel free to contact us and send an inquiry, email: brad@ihpa.net
In grubbs 2nd generation catalyst the phosphine ligand has been replaced with NHC. This has made it possible to do olefin metathesis in water and even ring-opening metathesis polymerization (ROMP) (see the picture). It is also more functional group tolerant than the first generation catalyst.
Hoveyda-Grubbs 1a and its related complexes have been shown to be excellent catalysts for asymmetric ring closing metathesis (RCM) reactions with small unsaturated amines. The catalysts can be prepared by facile anionic ligand exchange with carboxylate ligands, thereby achieving high enantioselectivity in RCM and ARCM reactions.
The reactivity of the Grubbs 1st and 2nd generation catalysts for atom-transfer radical copolymerization (ATRP) of methyl methacrylate (MMA) with ethyl methacrylate (EMA) was investigated. The reaction was carried out in a closed reflux condenser under argon. Both catalysts were found to be active, with the 1st generation catalyst giving higher reactivity than the 2nd generation catalyst.
N-heterocyclic carbenes (NHC) are ubiquitous ancillary ligands employed in metal-catalyzed homogeneous catalysis and polymerization reactions. Despite their widespread use, only limited progress has been achieved in understanding their reactivity. The reactivity of NHCs has been found to depend on the structure of the surrounding ligand. In this study, we have used a combination of distortion/interaction calculations (DEreorg and DEint) with DFT-based reactivity descriptors to investigate the differences in ruthenium-catalyzed olefin metathesis and ring-opening metathesis polymerization between the first and second generation Hoveyda-Grubbs catalysts. The catalysts have been shown to exhibit good tolerance for functional groups such as amide, ester and carboxylic acids.