Biotinylated Metathesis Catalysts: Synthesis and Performance in Ring Closing Metathesis
摘要:
Nine biotinylated Grubbs-Hoveyda and Grubbs-type metathesis catalysts were synthesized and evaluated in ring closing metathesis reactions of N-tosyl diallylamine and 5-hydroxy-2-vinylphenyl acrylate. Their catalytic activity in organic- and aqueous solvents was compared with the second generation Grubbs-Hoveyda catalyst. The position of the biotin-moiety on the N-heterocyclic carbene was found to critically influence the catalytic activity of the corresponding ruthenium-based catalysts.
A Fluorescent Molecular Probe for the Detection of Hydrogen Based on Oxidative Addition Reactions with Crabtree‐Type Hydrogenation Catalysts
作者:Pavlo Kos、Herbert Plenio
DOI:10.1002/anie.201506918
日期:2015.11.2
A Crabtree‐type IrI complex tagged with a fluorescent dye (bodipy) was synthesized. The oxidativeaddition of H2 converts the weakly fluorescent IrI complex (Φ=0.038) into a highly fluorescent IrIII species (Φ=0.51). This fluorogenic reaction can be utilized for the detection of H2 and to probe the oxidativeaddition step in the catalytic hydrogenation of olefins.
Development of Building Blocks for the Synthesis of N-Heterocyclic Carbene Ligands
作者:Guopin Xu、Scott R. Gilbertson
DOI:10.1021/ol0516521
日期:2005.10.1
The synthesis of a series of NHC building blocks that can then be incorporated into more complicated structures by palladium catalysis is reported. This approach is used for the synthesis of three amino acids containing NHC side chains. The ability to use the amino acids in solid-phase peptide synthesis to make NHC-containing peptides is also demonstrated. Additionally, the NHC side chain can be deprotected and coordinated to a catalytically active transition metal. Finally, it is illustrated that the building blocks participate in Suzuki coupling to provide access to substituted NHC ligands.