Contact Metathesis Polymerization

Because you release ring strain, ring opening metathesis polymerization (ROMP) of strained cyclic olefins (norbornenes, cyclooctadiene, etc.) is an exothermic reaction, which means once initiated it generates heat, and the rate increases until the reaction fizzles out. If you’re interested in molding a large part, this can be problematic since you don’t want your resin […]

Olefin Metathesis and Polyalkynes

Metal carbenes (species with a formal carbon-metal double bond) are intermediates in all olefin metathesis reactions. This is not the only reactivity that metal carbenes exhibit, however. With some metals (including ruthenium), an alkynyl carbene can undergo a bond reorganization to give a new alkynyl carbene (termed a metallotropic shift). If a molecule is set […]

Olefin Metathesis at the 239th ACS Meeting

The American Chemical Society (ACS) sponsors a bi-annual national meeting for chemists to introduce new ideas, communicate results, network, and build professional skills. This spring, the 239th ACS meeting is being held March 21st – 25th in San Francisco, CA, and the theme is “Chemistry for a Sustainable World”. As one might expect, olefin metathesis […]

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 […]

Storage of Grubbs Catalysts

“Anhydrous” means different things to different people. – Seth Herzon I’m sure you’ve seen it written, probably somewhere on this website, that ruthenium olefin metathesis catalysts are stable to air and water. But stability is not a black and white issue. It’s all grey area. So exactly how grey are Grubbs catalysts? For a typical […]

Overcoming Substrate Bias with Metathesis Catalyst Selection

When justifying natural product synthesis, it’s often said that total synthesis provides a vehicle for the discovery of novel modes of chemical reactivity that otherwise wouldn’t be noticed. A nice example of this concept in action is out this week from researchers in Brian Stoltz’s group.1 During a total synthesis of the natural product curvularin, […]

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 […]