A new tandem cross enyne metathesis (CEYM)-intramolecular Diels-Alder reaction (IMDAR) has been carried out. It involves conjugated ketones, esters or amides bearing a remote olefin and aromatic alkynes as the starting materials. The overall process enables the preparation of a small family of linear bicyclic scaffolds in a very simple manner with moderate to good levels of diastereoselectivity...

The largest industrial application of olefin metathesis today is the synthesis of propylene from ethylene and butenes employing WO3 on SiO2, a relatively long-lived and regenerable catalyst that operates at 350–400 °C. It is widely proposed that high temperatures are required because the percentage of metal sites actually involved in the metathesis reaction is extremely low, or the reaction tha...

The tandem catalysis of ring-closing metathesis/atom transfer radical reactions was investigated with the homobimetallic ruthenium-indenylidene complex [(p-cymene)Ru(μ-Cl)₃RuCl(3-phenyl-1-indenylidene)(PCy₃)] (1) to generate active species in situ. The two catalytic processes were first carried out independently in a case study before the whole sequence was optimized and applied to the synthesi...

This report presents a cost analysis of Polymer Grade (PG) Propylene production from ethylene and raffinate-2 using a metathesis process. The process examined is similar to CB&I Lummus Technology's Olefins Conversion Technology (OCT). In this process, Polymer Grade Propylene is produced through a metathesis reaction of ethylene with 2-butene, present in raffinate-2 feedstock. This report examin...

Two new precatalysts for ethylene and α-olefin trimerization, (FI)Ti(CH2SiMe3)2Me and (FI)Ti(CH2CMe3)2Me (FI = phenoxy-imine), have been synthesized and structurally characterized by X-ray diffraction. (FI)Ti(CH2SiMe3)2Me can be activated with 1 equiv of B(C6F5)3 at room temperature to give the solvent-separated ion pair [(FI)Ti(CH2SiMe3)2][MeB(C6F5)3], which catalytically trimerizes ethylene o...

The reaction of the phosphonium alkylidene [(H(2)IMes)RuCl(2)=CHP(Cy)(3))](+) BF(4)(-) with propene, 1-butene, and 1-hexene at -45 °C affords various substituted, metathesis-active ruthenacycles. These metallacycles were found to equilibrate over extended reaction times in response to decreases in ethylene concentrations, which favored increased populations of α-monosubstituted and α,α'-disubst...

A salt metathesis reaction is a chemical process involving the exchange of bonds between two reacting chemical species, which results in the creation of products with similar or identical bonding affiliations. Hyperstructure theory is studied from the theoretical point of view and for its applications. In this paper, we provide some examples of hyperstructures associated with salt m...

Density functional theory calculations have been used to explore the potential of Ru-based complexes with 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene (SIMes) ligand backbone (A) being modified in silico by the insertion of a C60 molecule (B and C), as olefin metathesis catalysts. To this end, we investigated the olefin metathesis reaction catalyzed by complexes A, B, and C using ethylene...

A relatively new class of three-dimensional ordered mesoporous silicates, KIT-6, incorporated with Earth-abundant metals such as Zr, Nb, and W (termed as M-KIT-6), show remarkable tunability of acidity and metal dispersion depending on the metal content, type, and synthetic method. The metal-incorporation is carried out using one-pot synthesis procedures that are amenable to easy scale-up. By s...

The reaction between adsorbed ethylene and methylene species has been investigated on a molybdenum-aluminum alloy grown from Mo(CO)(6) on a planar alumina film formed on a Mo(100) single crystal in ultrahigh vacuum. Di-sigma-bonded ethylene reacts with carbene species, formed on the surface from methylene iodide, to form a C(3) metallacycle. This predominantly decomposes to yield propylene, whi...