259268-91-2

Upstream product

• 300-57-2 allylbenzene 
• 25260-60-0 cis-1,4-bis(acetyloxy)but-2-ene 
• 546-67-8 lead(IV) tetraacetate 
• 72195-58-5 Tributyl-((E)-4-phenyl-but-2-enyl)-stannane 
• 768-56-9 4-Phenylbut-1-ene 
• 563-63-3 silver(I) acetate 
• 3375-31-3 palladium diacetate 
• 64-19-7 acetic acid 
• 127-09-3 sodium acetate 
• 4489-84-3 3-methyl-1-phenylbut-2-ene 
• 1576-98-3 1,4-diacetoxybut-2-ene 

Downstream Products

• 7492-40-2 4-phenylbutyl acetate 
• 874472-00-1 2-(3-Methyl-buta-1,2-dienyl)-2-((E)-4-phenyl-but-2-enyl)-malonic acid dimethyl ester 

Relevant academic research and scientific papers

New indenylidene-type metathesis catalysts bearing unsymmetrical N-heterocyclic ligands with mesityl and nitrobenzyl substituents

New indenylidene-type second generation catalysts bearing modified unsymmetrically substituted N- heterocyclic carbene ligands were synthesized. The com- plexes contain an N-mesityl and N?-nitrobenzyl substituted NHC ligand. The precursors of free carbenes—imidazolinium salts—were obtained in an easy and environment- friendly way (under aqueous or neat conditions). The new catalysts were prepared by reaction of in situ generated carbenes with a 1st generation indenylidene catalyst, containing pyridine ligands instead of tricyclohexylphosphine. The complexes were tested in RCM, CM, and ene-yne metathesis model reactions in commercial-grade solvents in air. Their activities were compared with that of commercially available indenylidene catalyst. The structures of complexes and their stability were investigated using static DFT calculations with mixed basis set.

A Ruthenium Catalyst for Olefin Metathesis Featuring an Anti-Bredt N-Heterocyclic Carbene Ligand

A ruthenium complex bearing an "anti-Bredt" N-heterocyclic carbene was synthesized, characterized and evaluated as a catalyst for olefin metathesis. Good conversions were observed at room temperature for the formation of di- A nd tri-substituted olefins b

Novel olefin metathesis ruthenium catalysts bearing backbone-substituted unsymmetrical NHC ligands

Stable Ru-based catalysts containing unsymmetrical N-heterocyclic carbene (NHC) ligands with phenyl substituents on the backbone in syn and anti stereochemical relationships have been easily prepared and fully characterized. Preliminary investigation reve

Helicenes as Chirality-Inducing Groups in Transition-Metal Catalysis: The First Helically Chiral Olefin Metathesis Catalyst

Helical chirality is a novel enantioselectivity-inducing property in transition-metal-catalyzed transformations. The principle is illustrated herein for the example of asymmetric olefin metathesis. This work reports the synthesis of the first helically chiral Ru-NHC alkylidene complex from an aminohelicene-derived imidazolium salt, which was ligated to the first generation Hoveyda–Grubbs catalyst. Kinetic data were acquired for benchmark test reactions and compared to an achiral catalyst. The helically chiral Ru-catalyst was evaluated in asymmetric ring-closing metathesis (RCM) and ring-opening metathesis–cross-metathesis (ROM/CM) reactions, which proceeded with promising levels of enantioselectivity. Extensive NMR-spectroscopic investigations and a DFT geometry optimization were performed. These results led to a topographic steric map and calculation of percent-buried-volume values for each quadrant around the metal center.

Synthesis of siloxy-modified second generation Hoveyda-Grubbs catalysts and their catalytic activity

Efficient syntheses of the first ruthenium alkylidene complexes bearing siloxide ligands are described. Second generation Hoveyda-Grubbs catalyst is shown to undergo efficient functionalization with a number of potassium silanolates to give disiloxy deriv

Ruthenabenzene: A Robust Precatalyst

Metallaaromatics constitute a unique class of aromatic compounds where one or more transition metal elements are incorporated into the aromatic system, the parent of which is metallabenzene. One of the main concerns about metallabenzenes generally deals with the structural characterization related to their relative aromaticity compared to the carbon archetype. Transition metal-containing metallabenzenes are also implicated in certain catalytic processes such as alkyne metathesis polymerization; however, these transition metal-based metallaaromatic compounds have not been developed as a catalyst. Herein, we describe an effective strategy to generate diverse arrays of ruthenabenzenes and demonstrated them as an aromatic equivalent of the Grubbs-type ruthenium alkylidene catalysts. These ruthenabenzenes can be prepared via an enyne metathesis and metallotropic [1,3]-shift cascade process to form alkyne-chelated ruthenium alkylidene intermediates followed by spontaneous cycloaromatization. The aromatic nature of these complexes was confirmed by spectroscopic and X-ray crystallographic data, and the mechanistic pathways for the cycloaromatization process were studied by DFT calculations. These ruthenabenzenes display robust catalytic activity for metathesis and other transformations, which illustrates that metallabenzenes are not only compounds of structural and theoretical interests but also are a novel platform for new catalyst development.

Activated Hoveyda-Grubbs Olefin Metathesis Catalysts Derived from a Large Scale Produced Pharmaceutical Intermediate – Sildenafil Aldehyde

Two EWG-activated Hoveyda-Grubbs-type ruthenium complexes (Sil-II and Sil-II’) were obtained, characterized, and screened in a set of olefin metathesis reactions. These catalysts were conveniently synthesized from a commercially available pharmaceutical building block – Sildenafil aldehyde – in two steps only. Stability and catalytic activity tests disclosed that the bulkier NHC-ligand bearing catalyst Sil-II’ is visibly more stable and productive than its smaller NHC-analogue Sil-II. Good application profile of catalyst Sil-II’ was confirmed in a set of diverse metathesis reactions including ring-closing metathesis (RCM) and cross-metathesis (CM) of complex polyfunctional substrates of medicinal chemistry interest, including a challenging macrocyclization of the Pacritinib precursor. Compatibility of the new catalyst with various green solvents was checked and metathesis of Sildenafil and Tadalafil-based substrates was successfully conducted in acetone. The mechanism of Sil-II’ initiation has been investigated through kinetic experiments unveiling that the decrease of the steric hindrance of the chelating alkoxy moiety (from iPrO to EtO) favors the interchange initiation pathway over the typical dissociation pathway for other popular 2nd generation Hoveyda-Grubbs catalysts. (Figure presented.).

In a Quest for Selectivity Paired with Activity: A Ruthenium Olefin Metathesis Catalyst Bearing an Unsymmetrical Phenanthrene-Based N-Heterocyclic Carbene

Robust, selective, and stable in the presence of ethylene, ruthenium olefin metathesis pre-catalyst, {[3-benzyl-1-(10-phenyl-9-phenanthryl)]-2-imidazolidinylidene}dichloro(o-isopropoxyphenylmethylene)ruthenium(II), Ru-3, bearing an unsymetrical N-heterocyclic carbene (uNHC) ligand, has been synthesized. The initiation rate of Ru-3 was examined by ring-closing metathesis and cross-metathesis reactions with a broad spectrum of olefins, showing an unprecendented selectivity. It was also tested in industrially relevant ethenolysis reactions of olefinic substrates from renewable feedstock with very good yields and selectivities.

Compositions And Methods For Visible-Light-Controlled Ruthenium-Catalyzed Olefin Metathesis

The present disclosure provides compositions and methods for metathesizing a first alkenyl or alkynyl group with a second alkenyl or alkynyl group, the composition comprising a ruthenium metathesis catalyst and a photoredox catalyst that is activated by v

Specialized ruthenium olefin metathesis catalysts bearing bulky unsymmetrical NHC Ligands: Computations, synthesis, and application

Second-generation ruthenium olefin metathesis catalysts were investigated with systematic variation of the unsymmetrical uNHC ligands. Depending on the uNHC steric bulk, the catalysts exhibited different activity and selectivity in metathesis reactions. DFT calculations and X-ray crystallographic data were used to understand the influence of uNHC ligand structure on the catalyst properties. Furthermore, the catalysts were examined in the context of reactions that are problematic for general-purpose Ru catalysts, including industrially important self-cross metathesis of α-olefins and ethenolysis of ethyl oleate.