Grubbs catalyst 2nd generation

Chemical properties

pink-brown to red-purple crystals or powder

Characteristics

Grubbs catalyst is a kind of coordination compound used in olefin metathesis reaction, and the ligand in it has a great influence on the catalytic performance and stability of the catalyst. Grubbs second-generation catalysts are more active than first-generation catalysts and have a wider substrate range, including sterically demanding or deactivated olefins such as 1,1-disubstituted olefins and α,β-non- Saturated carbonyl compounds.

The Uses of Grubbs catalyst 2nd generation

suzuki reaction

The Uses of Grubbs catalyst 2nd generation

Grubbs Catalyst^? M204 can be used as a catalyst for ring-closing metathesis (RCM), cross-metathesis, and ring-opening metathesis polymerization (ROMP). It is also used to synthesize trisubstituted olefins with excellent functional group tolerance and selectivity via cross-metathesis and ring closing metathesis reactions.
It can also be used as a catalyst:

• To synthesize coumarins from phenolic compounds via RCM.
• To cleave secondary (E)-allyl vic-diols to aldehydes.

Definition

Adlhart and Chen found that ligand rotation is the difference between the activity of the first and second-generation Grubbs catalysts. This difference is brought about by a difference in the symmetry of the ligands. The phosphine ligand has a threefold symmetry, which causes a high barrier in the middle of the reaction coordinate, which is forced by the need for rotation of the phosphine. However, the barrier is absent for the second-generation Grubbs catalyst, with twofold symmetry of the NHC ligand. The rate-limiting step for second-generation catalysts is always phosphine dissociation[2].