News Update on Imidazol Research: Sep – 2019

Ruthenium Carbene Complexes with N,N‘-Bis(mesityl)imidazol-2-ylidene Ligands: RCM Catalysts of Extended Scope

The atomic number 44 carbene complexes 3a,b bearing imidazol-2-ylidene ligands represent wonderful precatalysts for ring-closing metathesis (RCM) reactions permitting the formation of tri- and tetrasubstituted cycloalkenes. They conjointly apply to annulations that square measure on the far side the scope of the quality Grubbs carbene one moreover on ring-closing reactions of propenoic acid derivatives even though the ensuing α,β-unsaturated lactones (or lactams) square measure tri- or tetrasubstituted. The reactivity of 3a was found to be extremely obsessed on the reaction medium: significantly high reaction rates square measure discovered in methylbenzene, though this solvent conjointly ends up in Associate in Nursing accrued tendency of the catalyst to isomerize the double bonds of the substrates. [1]

PAA/imidazol-based proton conducting polymer electrolytes

Anhydrous nucleon conducting chemical compound electrolytes are ready by entrapping imidazol (Im) in polyacrylic acid (PAA) with numerous ratio ratios, x, to make PAAxIm (x is that the range of moles of Im per chemical compound repeat unit). chemical compound electrolytes, PAAxIm (with x=0.5 and 1) will be solid into clear, homogenized films. FT-IR results indicate the protonation of imidazol. thermohydrometric analysis (TG) illustrates that these blends are with chemicals stable up to concerning a hundred and sixty °C. Differential scanning mensuration (DSC) shows that tumbler transition temperature decrease from fifty seven °C for x=0.5 to thirty five °C for x=1. The dc conduction will increase with x and temperature reaching ∼10−3 S/cm for x=1 at one hundred twenty °C. [2]

Optically Active Iridium Imidazol-2-ylidene-oxazoline Complexes:  Preparation and Use in Asymmetric Hydrogenation of Arylalkenes

This work explores the potential of metal complexes of the N-heterocyclic carbene oxazoline ligands one in uneven hydrogenations of arylalkenes. The accessible carbene precursors, imidazolium salts two, and sturdy metal complexes five expedited a discovery/optimization approach that featured preparation of atiny low library of metal complexes, parallel chemical process reactions, and automatic analysis. 3 of the complexes (5ab, 5ad, and 5dp) and an analogous Rh advanced (6ap) were studied by single-crystal diffraction techniques. This unconcealed molecular options of 6ap, and presumptively the corresponding metal advanced 5ap, that the others don’t have. In enantioselective hydrogenations of arylalkenes advanced 5ap was the most effective for several, however not all, substrates. The enantioselectivities and conversions determined were sensitive to minor changes to the catalyst and substrate structure. [3]

Synthesis of 5-Bromouridine Oligonucleotides by the Reaction of 5-Bromouridine with Tri(imidazol-1-yl)phosphine

5-Bromouridine oligonucleotides were synthesized directly from 5-bromouridine by a polycondensation technique. The reaction of 5-bromouridine with tri(imidazol-1-yl)phosphine was meted out at a comparatively coldness and therefore the resulting in place chemical reaction of the resulting phosphite oligomer was achieved with iodine and water. 5-Bromouridine oligonucleotides up to a hexamer were obtained in high yields. The phosphodiester linkage of the oligomer consists of each 3′,5′- and 2′,5′-linkages. The interaction of 5-bromouridine oligonucleotides with poly A was investigated. [4]

Computational Chemistry Studies on the Adsorption/Corrosion Inhibitive Potential of 2-(2-heptadecyl-4,5-dihydro-1H-imidazol-1-yl) ethan-1-ol on Iron Surface at Different Temperatures

A procedure study on 2-(2-heptadecyl-4,5-dihydro-1H-imidazol-1-yl) ethan-1-ol (HDDH) was dispensed to work out the adsorption/corrosion inhibitive potential at the temperatures of 60ºC and eighty ºC on iron surface victimization the fabric Studio software system. For this purpose, Molecular dynamic simulation and quantum chemical calculations were accustomed calculate totally different chemical parameters like the energy of the very best occupied molecular orbital (EHOMO), energy of the bottom unoccupied molecular orbital (ELUMO), ionization potential (IE), tendency (χ), lepton affinity (EA), world hardness (η), world softness (σ), variety of lepton transfer (ΔN), electrophilicity index (ω), moment (m ), energy of deformation (Đ), van der Waal accessible surface (ʌ), others embrace interaction energy, energy, molecular energy and minimum distance between HDDH and iron surface, to predict the adsorption/corrosion inhibitive potential of HDDH. [5]

Reference

[1] Fürstner, A., Thiel, O.R., Ackermann, L., Schanz, H.J. and Nolan, S.P., 2000. Ruthenium carbene complexes with N, N ‘-bis (mesityl) imidazol-2-ylidene ligands: RCM catalysts of extended scope. The Journal of organic chemistry, 65(7), pp.2204-2207. (Web Link)

[2] Bozkurt, A., Meyer, W.H. and Wegner, G., 2003. PAA/imidazol-based proton conducting polymer electrolytes. Journal of Power Sources, 123(2), pp.126-131. (Web Link)

[3] Perry, M.C., Cui, X., Powell, M.T., Hou, D.R., Reibenspies, J.H. and Burgess, K., 2003. Optically active iridium imidazol-2-ylidene-oxazoline complexes: preparation and use in asymmetric hydrogenation of arylalkenes. Journal of the American Chemical Society, 125(1), pp.113-123. (Web Link)

[4] Synthesis of 5-Bromouridine Oligonucleotides by the Reaction of 5-Bromouridine with Tri(imidazol-1-yl)phosphine
Takeo Shimidzu & Kazushige Yamana
Polymer Journalvolume 15, pages727–732 (1983) (Web Link)

[5] J. Uwakwe, K. and I. Obike, A. (2017) “Computational Chemistry Studies on the Adsorption/Corrosion Inhibitive Potential of 2-(2-heptadecyl-4,5-dihydro-1H-imidazol-1-yl) ethan-1-ol on Iron Surface at Different Temperatures”, International Research Journal of Pure and Applied Chemistry, 15(2), pp. 1-11. doi: 10.9734/IRJPAC/2017/37402. (Web Link)