scholarly journals NHC Ligand Effects on Ru-Catalyzed Cross-Metathesis of Renewable Materials

Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 904
Author(s):  
Veronica Paradiso ◽  
Raffaele Contino ◽  
Fabia Grisi
Keyword(s):  
Renewable Resources ◽  
Olefin Metathesis ◽  
Ethyl Oleate ◽  
Building Blocks ◽  
Metathesis Reaction ◽  
Renewable Materials ◽  
Ligand Effects ◽  
Cross Metathesis ◽  
Chemical Manufacturing ◽  
Catalytic Performances

As petrochemical resources become increasingly scarce and expensive, much attention has been focused on renewable resources from biomass as alternative options for producing basic building blocks for chemical manufacturing. Catalytic olefin metathesis represents a powerful tool to transform biosourced structural motifs in valuable commodity, fine, and specialty chemicals. In that respect, the appropriate choice of the catalyst is the key issue of each metathesis transformation. The current study examines the influence of different N-heterocyclic carbene (NHC) ligands containing one or two N-alkyl substituents on the efficiency of Hoveyda–Grubbs-type catalysts in the cross-metathesis reaction of ethyl oleate with cis-1,4-diacetoxy-2-butene and cross-metathesis of eugenol acetate with cis-1,4-dichloro-2-butene. Interestingly, the introduction of alkyl N-substituents in the NHC ligand was revealed as beneficial for catalytic performances in the examined cross-metathesis (CM) reactions, leading to higher activity and/or selectivity than those observed in the presence of the classical, commercially available Hoveyda–Grubbs second generation catalyst (HGII).

A facile new procedure for the deprotection of allyl ethers under mild conditions

2000 ◽  
Vol 78 (6) ◽  
pp. 838-845 ◽  
Author(s):  
Yun-Jin Hu ◽  
Romyr Dominique ◽  
Sanjoy Kumar Das ◽  
René Roy
Keyword(s):  
Key Words ◽  
Catalytic System ◽  
Olefin Metathesis ◽  
Allyl Ether ◽  
Metathesis Reaction ◽  
Grubbs Catalyst ◽  
Allyl Ethers ◽  
Mild Conditions ◽  
Cross Metathesis ◽  
Allylic Ethers

A novel isomerization of O-allyl glycosides into prop-1-enyl glycosides was observed instead of cross-metathesis during an olefin metathesis reaction using Grubbs' ruthenium benzylidene catalyst (Cy3P)2RuCl2=CHPh (1), N-allyltritylamine, and N,N-diisopropylethylamine as necessary auxiliary reagents. In the search for a better catalytic system, it has been found that dichlorotris(triphenylphosphine)ruthenium(II), [(C6H5)3P]3RuCl2, (2) was much more efficient for the isomerization of allylic ethers. The labile prop-1-enyl group was easily hydrolyzed using HgCl2-HgO and the hemiacetals (25-32) were isolated in excellent yields (ca. 90%).Key words: allyl ether, carbohydrate, Grubbs' catalyst, isomerization, metathesis, deprotection.

scholarly journals Electrochemical reduction of acetonitrile to ethylamine

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rong Xia ◽  
Dong Tian ◽  
Shyam Kattel ◽  
Bjorn Hasa ◽  
Haeun Shin ◽  
...  
Keyword(s):  
Computational Study ◽  
Building Blocks ◽  
Primary Amines ◽  
Hydrogen Electrode ◽  
Faradaic Efficiency ◽  
Fossil Energy ◽  
Chemical Manufacturing ◽  
Stable Performance ◽  
Temperature And Pressure ◽  
Partial Current

AbstractElectrifying chemical manufacturing using renewable energy is an attractive approach to reduce the dependence on fossil energy sources in chemical industries. Primary amines are important organic building blocks; however, the synthesis is often hindered by the poor selectivity because of the formation of secondary and tertiary amine byproducts. Herein, we report an electrocatalytic route to produce ethylamine selectively through an electroreduction of acetonitrile at ambient temperature and pressure. Among all the electrocatalysts, Cu nanoparticles exhibit the highest ethylamine Faradaic efficiency (~96%) at −0.29 V versus reversible hydrogen electrode. Under optimal conditions, we achieve an ethylamine partial current density of 846 mA cm−2. A 20-hour stable performance is demonstrated on Cu at 100 mA cm−2 with an 86% ethylamine Faradaic efficiency. Moreover, the reaction mechanism is investigated by computational study, which suggests the high ethylamine selectivity on Cu is due to the moderate binding affinity for the reaction intermediates.

Complete Stereocontrol in the Synthesis of Harmonine and Novel Analogues Facilitated by a Grubbs Z-Selective Cross-Metathesis Catalyst

2015 ◽  
Vol 68 (12) ◽  
pp. 1815 ◽  
Author(s):  
Steven-Alan G. Abel ◽  
Wesley J. Olivier ◽  
Richard L. Pederson ◽  
Alex C. Bissember ◽  
Jason A. Smith
Keyword(s):  
The Self ◽  
Metathesis Reaction ◽  
Cross Metathesis ◽  
Metathesis Catalyst ◽  
The Cross

(R)-Harmonine was synthesised in 15 % overall yield via a six-step sequence exploiting a Z-selective cross-metathesis reaction as its centrepiece. By this strategy, the cis-olefin present in the target could be installed exclusively. The use of an alcohol and an ester as the amine precursors was crucial for isolating the cross-metathesis product from the self-metathesis products. This method was also used to prepare two novel analogues of harmonine.

A succinct access to ω-hydroxylated jasmonates via olefin metathesis

2017 ◽  
Vol 72 (7-8) ◽  
pp. 285-292 ◽  
Author(s):  
Guillermo H. Jimenez-Aleman ◽  
Selina Seçinti ◽  
Wilhelm Boland
Keyword(s):  
Abiotic Stress ◽  
Olefin Metathesis ◽  
Higher Plants ◽  
Environmentally Friendly ◽  
Signaling Molecules ◽  
Synthetic Route ◽  
Limited Availability ◽  
Cross Metathesis ◽  
Physiological Processes

AbstractIn higher plants, jasmonates are lipid-derived signaling molecules that control many physiological processes, including responses to abiotic stress, defenses against insects and pathogens, and development. Among jasmonates, ω-oxidized compounds form an important subfamily. The biological roles of these ω-modified derivatives are not fully understood, largely due to their limited availability. Herein, a brief (two-step), simple and efficient (>80% yield), versatile, gram-scalable, and environmentally friendly synthetic route to ω-oxidized jasmonates is described. The approach utilizes olefin cross-metathesis as the key step employing inexpensive, commercially available substrates and catalysts.

scholarly journals Mechanistic Investigations of the Iron(III)-Catalyzed Carbonyl-Olefin Metathesis Reaction

2017 ◽  
Vol 139 (31) ◽  
pp. 10832-10842 ◽  
Author(s):  
Jacob R. Ludwig ◽  
Susan Phan ◽  
Christopher C. McAtee ◽  
Paul M. Zimmerman ◽  
James J. Devery ◽  
...  
Keyword(s):  
Olefin Metathesis ◽  
Metathesis Reaction ◽  
Mechanistic Investigations

scholarly journals Synthesis of 2-aminosuberic acid derivatives as components of some histone deacetylase inhibiting cyclic tetrapeptides

2017 ◽  
Vol 13 ◽  
pp. 2153-2156 ◽  
Author(s):  
Shital Kumar Chattopadhyay ◽  
Suman Sil ◽  
Jyoti Prasad Mukherjee
Keyword(s):  
Amino Acid ◽  
Histone Deacetylase ◽  
Building Block ◽  
Suberic Acid ◽  
Metathesis Reaction ◽  
Cross Metathesis ◽  
Important Amino Acid ◽  
New Synthesis ◽  
Cyclic Tetrapeptides ◽  
Derivatives Of

A new synthesis of the important amino acid 2-aminosuberic acid from aspartic acid is reported. The methodology involves the alternate preparation of (S)-2-aminohept-6-enoate ester as a building block and its diversification through a cross-metathesis reaction to prepare the title compounds. The utility of the protocol is demonstrated through the preparation of three suberic acid derivatives of relevance to the design and the synthesis of peptides of biological relevance.

Sign in / Sign up

Export Citation Format

Share Document