Higman, C.S.; Rufh, S.A.; McDonald, R.; Fogg, D.E. “Synthesis and Dynamic Behavior of a Dimeric Ruthenium Benzylidene Complex Bearing a Truncated N-Heterocyclic Carbene Ligand” J. Organomet. Chem. 2017, Advance Article. DOI: 10.1016/j.jorganchem.2017.03.033 As the use of metathesis catalysts has become more prevalent in industry, understanding the decomposition pathway is crucial. The Fogg group at the […]
New Precatalysts for Improved E-Selective Cross-Metathesis Activity
Ahmed, T.S.; Grubbs, R. H. “Fast-Initiating, Ruthenium-based Catalysts for Improved Activity in Highly E-Selective Cross Metathesis” J. Am. Chem. Soc., 2017, 139, 1532-1537. [10.1021/jacs.6b11330] A recent publication from the Grubbs’ group details an evolved dithiolate-ligated ruthenium precatalyst (Figure 1) that displays enhanced initiation kinetics resulting in decreased reaction times and improved isolated yields. These new […]
Diisopropylphenyl 2nd Generation Hoveyda Catalyst
Diisopropylphenyl 2nd Generation Hoveyda Catalyst1 – CAS#: [635679-24-2] – FW: 711 – Color: Green – Initiation temperature: >0 °C Process Strengths Weaknesses CM -Highly efficient in reactions involving ethylene -Most efficient reported catalyst for forming (most) trisubstituted olefins by CM -Hindered substrates Despite its first report in the literature in 2003,1 this catalyst has received […]
Diisopropylphenyl 2nd Generation Grubbs Catalyst
Diisopropylphenyl 2nd Generation Grubbs Catalyst1 (PCy3 = tricyclohexylphosphine) – CAS#: [373640-75-6] – FW: 933 – Color: Brown – Initiation temperature: 0 °C
Chelating Pyridine Catalyst
Chelating Pyridine Catalyst1 – CAS#: [801219-49-8] – FW: 598 – Color: Green – Initiation temperature: >60 °C Process Strengths Weaknesses CM -Requires elevated temperatures for initiation ROMP -Latent initiator allows for ease of handling of polymer resin prior to initiation This catalyst is a latent initiator that possesses the high activity of […]
1st Generation Piers Catalyst
1st Generation Piers Catalyst1 (PCy3 = tricyclohexylphosphine) – CAS#: [1020085-61-3] – FW: 833 – Color: Black – Initiation temperature: <0 °C Process Strengths Weaknesses CM -Synthesis of 1,2-disubstituted olefins from terminal olefins-Ethenolysis of internal olefins to make terminal olefins -Formation of trisubstituted olefins-Electron-deficient substrates-Hindered substrates RCM -Synthesis of 1,2-disubstituted olefins -Typically forms the kinetic E/Z […]
ortho-Tolyl 2nd Generation Grubbs Catalyst
ortho-Tolyl 2nd Generation Grubbs Catalyst1 (Ph = phenyl) – CAS#: [927429-60-5] – FW: 793.28 – Color: Brown – Initiation temperature: >20 °C Process Strengths Weaknesses CM -hindered alpha olefins -trisubstituted olefins RCM -sterically hindered di- and tri-substituted olefins -tetrasubstituted olefins This catalyst was the product of a rational design effort to make catalysts […]
2nd Generation Grubbs Dimethylvinyl Alkylidene Catalyst
2nd Generation Grubbs Dimethylvinyl Alkylidene Catalyst (PCy3 = tricyclohexylphosphine) – CAS#: [253688-91-4] – FW: 826.97 – Color: Brown – Initiation temperature: >50 °C Process Strengths Weaknesses CM -Synthesis of 1,2-disubstituted olefins from terminal olefins-Ethenolysis of internal olefins to make terminal olefins-ADMET of unhindered terminal olefins -Formation of trisubstituted olefins-Electron-deficient substrates-Hindered substrates RCM -Synthesis of 1,2-disubstituted […]
2nd Generation Piers Catalyst
2nd Generation Piers Catalyst1 (PCy3 = tricyclohexylphosphine) – CAS#: [832146-68-6] – FW: 858.67 – Color: Brown – Initiation temperature: <0 °C Process Strengths Weaknesses CM -Synthesis of 1,2-disubstituted olefins from terminal olefins -Slower than 2nd Generation Grubbs Catalyst for CM of internal olefins RCM -Synthesis of 1,2-disubstituted and trisubstituted olefins -Reacts at low temperatures -Hindered […]
1st Generation Grubbs Dimethylvinyl Alkylidene Catalyst
1st Generation Grubbs Dimethylvinyl Alkylidene Catalyst1 (PCy3 = tricyclohexylphosphine) – CAS#: [194659-03-9] – FW: 800.95 – Color: Purple – Initiation temperature: >20 °C Process Strengths Weaknesses CM2 -Synthesis of 1,2-disubstituted olefins from terminal olefins-Ethenolysis of internal olefins to make terminal olefins-ADMET of unhindered terminal olefins -Formation of trisubstituted olefins-Low reactivity with electron-deficient and hindered substrates RCM -1,2-Disubstituted olefin formation-Typically […]
Unhindered Hoveyda-Grubbs Catalyst
ortho-Tolyl Hoveyda-Grubbs Catalyst1 – CAS#: [927429-61-6] – FW: 570.62 – Color: Green – Initiation temperature: >20 °C Process Strengths Weaknesses CM -CM of hindered terminal olefins2 -slower than Hoveyda-Grubbs 2nd gen catalyst in some instances -unfavorable for synthesis of trisubstituted olefins RCM -Tetra-substituted olefins -Hindered substrates This Hoveyda-Grubbs analog has ortho-tolyl substituents on the N-heterocyclic carbene […]