2020
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Item Carbon-supported copper-organic framework as active catalysts for acetylene hydrochlorination(Canadian Science Publishing, 2020-12-18) Wu, Yi-Bo; Ma, Yao; Li, Qingbin; Li, Songtian; Han, Yongjun; Li, Fu-XiangIn this work, activated carbon supported Cu-MOF as an acetylene hydrochlorination catalyst for manufacture vinyl chloride. Cu-MOF/AC with 15 wt% Cu-MOF content behaves the initial acetylene conversion of 99.2% and vinyl chloride selectivity of 98.5% at 200C. By combing steady-state experiments and physical-chemical characterization results (XPS, BET, H2-TPR, C2H2-TPD, XRD and HCl adsorption experiments), Cu-O-C is shown to retard the reduction of Cu2+, improve the reactants adsorption and strengthen the anti-coking ability of Cu-based catalysts. According to the previous studies and the Rideal-Eley mechanism, it is proposed that Cu2+ first adsorbed C2H2 to generate transition states in catalysis acetylene hydrochlorination.Item Colorimetric Properties and Structural Evolution of Cathodic Electrochromic WO3 Thin Films(Canadian Science Publishing, 2020-10-11) Dong, Dongmei; Robichaud, Jacques; Djaoued, YahiaCathodic amorphous tungsten trioxide (WO3) thin films have been deposited by reactive direct current magnetron sputtering and have been studied for their colorimetric and electrochromic properties. Those studies were carried out under two different potential cycling process: (i) switching mode (the response between coloration and bleaching in increasing potential steps) and (ii) modulation mode (the stepwise modulation to coloration with increasing potential and back to bleaching). Optical measurements, performed as a function of applied potential, showed excellent transmittance contrasts (∼80%) between colored and bleached states. The color stimuli and the changes that take place upon reversible switching or modulation were recorded based on the Commisson International de l’Éclairage (CIE) system. It was found that, under various potentials, significant changes occurred in the hue and saturation for WO3, as exhibited by the CIE 1931 xy chromaticity coordinates. As WO3 was reduced (W6+ + e– → W5+), a sharp decrease in luminance was observed. Excellent reversibility is demonstrated not only by colorimetric properties, but also by the corresponding intrinsic structures of the films, as investigated by µ-Raman spectroscopy. Furthermore, the WO3 films displayed a fast response time and good long-term cycling durability, which was attributed to their amorphous nature.Item Facile Preparation of Liposomes-encapsulated Zn-DTPA from Soy Lecithin for Decorporation of Radioactive Actinides(Canadian Science Publishing, 2020-09-28) Almalki, Manal; Lai, Edward; Ko, Raymond; Li, ChunshengDiethylenetriaminepentaacetic acid (DTPA) is an attractive decorporation agent that can enhance the excretion of radioactive actinides such as plutonium, americium, and curium after a radiological incident. However, DTPA is excreted in a short period of time after administration. Several formulations have been developed to improve DTPA pharmacokinetic properties. In this project, liposomes were prepared facilely from soy lecithin as a nanocarrier for pulmonary delivery of Zn-DTPA. Lipid hydration, reverse phase evaporation, and mechanical sonication were three methods evaluated for the preparation of liposomes-encapsulated Zn-DTPA. Mechanical sonication was the method of choice due to simple apparatus and facile preparation. Liposomes-encapsulated Zn-DTPA (lipo-Zn-DTPA) exhibited a hydrodynamic diameter of 178(2) nm and a spherical shape. The loading capacity and encapsulation efficiency of Zn-DTPA were 41(5) mg/g and 10(1)%, respectively. Lyophilization of lipo-Zn-DTPA for extended storage did not affect the amount of encapsulated drug or damage the structure of liposomes. An in vivo cytotoxicity test confirmed no serious adverse effect of Zn-DTPA encapsulated lecithin liposomes in rats.Item Design and synthesis of new tripod-chromogenic sensor based on s-triazine and thiazolidine-2,4-dione ring (TCST) for naked-eye detection of Li+(Canadian Science Publishing, 2020-12-31) Yazdani Nyaki, Hadiseh; Mahmoodi, Nosrat; Pasandideh Nadamani, MeysamA novel tripod-chromogenic sensor contains central nucleus s-triazine and thiazolidine-2,4-dione ring (TCST) was designed, synthesized and applied as colorimetric probes in aqueous solutions of dimethyl sulfoxide (DMSO). The probe showed a highly sensitive and selective colorimetric sensor for naked-eye detection of Li+, with a different color change from colorless to yellow. The probe’s detection limit (LOD) toward Li+ was found to be 1.2 μM. The result of the Job’s plot showed 1:1 stoichiometry for the interaction between tripod-chemosensor and Li+ that this result was confirmed by 1H NMR titration experiments. The probe can also be used for biological activities depending on the results of microbial tests.Item Phosphorus Promoted HZSM-5 Zeolites for the Coupling Transformation of Methanol with 1-Butene to Propylene(Canadian Science Publishing, 2020-12-06) Tang, Xiao-hua; Liu, Rui-qiang; Tian, Hai-feng; Li, Hui; zha, fei; Chang, YuePhosphorus promoted HZSM-5 zeolites (P-HZSM-5) were prepared by synthetic methods of incipient wetness impregnation and in-situ synthesis, respectively. It was characterized by the means of XRD, SEM, BET, TG and NH3-TPD. The P-HZSM-5 zeolite prepared by incipient wetness impregnation has a large specific surface area and pore size, and the weak acidity is remarkably increased. The catalytic activity of P-HZSM-5 for the coupling transformation of methanol with 1-butene to propylene was investigated. Under the reaction conditions of temperature at 550 ℃, pressure at 0.4 MPa, space velocity at 1800 mL/(gcath) and mole ratio of CH3OH/C4H8 to 1:1, the conversion of C4H8 can reach to 75.8%, and the selectivity and yield of propylene are 42.2% and 31.9%, respectively.Item Antidepressant-like effects of a new dihydro isoquinoline and its chemical precursors in mice. Involvement of serotonin and dopaminergic systems.(Canadian Science Publishing, 2020-11-23) Porras-Ramrez, Javier; Estrada-Reyes, Rosa; Rodrguez-Zavala, Jos Salud; Dorantes-Barrn, Ana Mara; Jurado-Hernndez, No; Martnez-Vzquez, MarianoAbstract This study was aimed to synthesize novel 2-(2-bromophenyl)-N-phenethylacetamides and benzylisoquinoline (BIQ) derivatives to be evaluated as antidepressant-like agents in mice. The N-phenethylacetamides derivatives were synthesized by coupling aromatic amides to the backbone of 2-bromophenylacetyl chloride. The synthesis of BIQ was achieved by the reaction between synthesized phenethylacetamides and 2-chloropyridine. The structures of the compounds were established mainly by 1D and 2D NMR spectra. Those compounds obtained with moderate to good yields were evaluated as antidepressant-like agents in the forced swimming test and the open field paradigms in mice. The possible mechanism of those active derivatives was explored by antagonist experiments in combination with p-chloro-phenylalanine methyl ester, reserpine, sulpiride, and dopamine D1 antagonist SCH23390. Also, MAO A and B inhibition assay were performed. Docking studies of the human dopamine D3 receptor with the most active compound was performed. The results showed that the (2-bromophenyl) (3,4-dihydroisoquinoline-1-yl)methanone (4a) presented the most potent antidepressant-like effects without modifying the ambulatory activity of experimental mice. Antagonist experiments showed that 4a acted on the serotonergic and dopaminergic receptors. Docking studies indicated a strong affinity of the human dopamine D3 receptor for 4a. Our results showed that benzylisoquinoline 4a has an antidepressant-like effect that is mediated at least in part by an interaction with the presynaptic serotonin receptors, and dopaminergic D1, D2, and D3, receptors. This study highlights the pharmacological potential of halogenated BIQ’s in the treatment of some depressive disorders.Item Designed electrochemical sensor based on metallocene modified conducting polymer composite for effective determination of tramadol in real samples(Canadian Science Publishing, 2020-11-10) Atta, Nada F.; Abdo, Ghada; Elzatahry, Ahmed; Galal, Ahmed; Hassan, SamarA novel composite for the electrochemical sensing of tramadol (Tr) was developed by the inclusion of metallocene mediator between two layers of conducting poly(3,4-ethylenedioxythiophene) (PEDOT) polymer, in presence of sodium dodecyl sulfate (SDS); (P/mediator/P…SDS). Three charge transfer mediators were evaluated: ferrocene carboxylic acid (FC1), ferrocene (FC2) and cobaltocene (CC) for Tr electrocatalytic oxidation. FC1-charge mediator showed relatively higher current response that was assisted by the electronic conduction of the polymer film. Moreover, SDS presented a great impact, resulting in the enhancement of the preconcentration/accumulation of Tr ions at the interface leading to faster electron transfer. In addition, the practical application of the proposed FC1 composite for the determination of Tr in real urine and serum samples was successfully achieved with adequate recovery results. Very low detection limits of 18.6 nM and 16 nM in the linear dynamic ranges of 7 M to 300 M and 5 M to 280 M, respectively, were obtained at the proposed sensor. Furthermore, the simultaneous determination of of Tr with common interfering species; paracetamol (PAPA), morphine (MO), dopamine (DA), ascorbic acid (AA) and uric acid (UA) proved excellent with good resolution and large potential peaks separation. The excellent characteristics of the proposed composite such as high reproducibility, good sensitivity, selectivity, anti-interference ability and good stability enhanced its application for determination of other narcotics drugs.Item Domestic-microwave-assisted one-step co-precipitation of Ag-CuO nanocomposite of Cu/Ag ratio optimized for photocatalysis and comparison with blending CuO with Ag nanoparticles(Canadian Science Publishing, 2020-11-11) Emara, Mahmoud Mohamed; Ahmed, Shaimaa Khamis; El-Dissouky, AliAg-CuO metal-semiconductor nanocomposite (NC) is an important component in various nanomaterial-based applications. Several approaches have been studied to facilitate its synthesis. However, most of them encounter some drawbacks. In the present work, we show synthesis of Ag-CuO NCs through one-pot co-precipitation with the aid of simple starting chemicals and measures including metal nitrates, hexamine, Agar, and domestic microwave heating. Photocatalyzed degradation of Congo Red in addition to the structural and optical characteristics show that this method is successful in production of Schottky barrier in Ag-CuO NCs with improved photocatalytic activity (PCA). Changing Cu content shows that the NC is not successfully formed at low Cu mol%. Consequently, the PCA of Ag-CuO of low Cu (2-6%) lies within 4.5∗10-4 -5.1∗10-4 min.-1, which is even lower than those of plain Ag and CuO nanoparticles (6.0∗10-4 -8.1∗10-4 min.-1, respectively). 60 mol% was the optimum Cu content with the highest PCA (18.8∗10-4 min.-1). Blending plain Ag and CuO nanoparticles to mimic the co-precipitated 60 mol% Ag-CuO showed very low PCA, even lower than the plain Ag and CuO, which once again confirms the efficiency of the followed simple one-pot co-precipitation approach in producing Ag-CuO with Schottky barrier and promoted PCA.Item The Thermochemical, Structural, and Spectroscopic Analyses of the Tautomers of Sulfur and Selenium Modified Emissive Nucleobases(Canadian Science Publishing, 2020-11-08) Parshotam, Shyam; Joy, Megan; Rossano-Tapia, Maria; Mora-Gomez, Victor Arturo; Brown, AlexIn this study, density functional theory (DFT) and time dependent density functional theory (TD-DFT) are used to investigate the stabilities and spectral properties [IR, UV-vis, and two-photon absorption (2PA)] of two sets of modified RNA nucleobase tautomers. The modifications introduce either a sulfur or selenium atom to form an isothiazolo[4,3-d]pyrimidine or isoselenazolo[4,3-d]pyrimidine heterocylic core respectively. The relative stabilities of both sets of modified tautomers determined with B3LYP/6-31++G(d,p) reveal that in water (with a polarizable continuum model) the 6-keto-2-amino tautomer of guanine and the rare 4-imino-2-keto tautomer of cytosine may be present at significant populations while the 6-enol-2-amino tautomer of guanine is more common in the gas phase. The identification of these modified tautomers due the natural differences in their vibrational modes and hence IR spectra is possible. Furthermore, the photophysical properties of both these sets of modified tautomers indicate that excitation and emission energies are shifted relative to their more abundant form in both one photon absorption and emission, and two-photon absorption (2PA) spectra as determined at the B3LYP/6-31++G(d,p) and CAM-B3LYP/aug-cc-pVDZ levels of theory, respectively. Even though the 2PA cross sections in water for all of the species are small (0.3 - 2.3 GM), the modified cytosine tautomer shows promise as its cross section is larger than the more dominant form. The spectral separation between the dominant form and the tautomers of isoselenazole and isothiazole modified cytosine and guanine are relatively similar, suggesting both modifications could be useful in elucidating the tautomers from their more abundant counterparts.Item Synthesis and Polarity-Sensitive Fluorescent Properties of a Novel Water-Soluble Polycyclic Aromatic Hydrocarbon (PAH)(Canadian Science Publishing, 2020-11-17) Sweet, Samantha Dena; Coulson, Drew Robert; Gigure, Jean-Benot; Morin, Jean-Francois; Wagner, Brian D.We report the successful synthesis and spectroscopic characterization of a novel, water soluble anthanthrene-based derivative, 6,12-bis(TEG)anthanthrene 3. The presence of the two long ethylene glycol side chains gives this large, 6-membered polycyclic aromatic compound a high aqueous solubility. It exhibits UV-visible absorption properties similar to those of anthanthrene itself, indicating that the side chains do not have a significant effect on the electronic structure of the central chromophore. The compound exhibits strong, polarity-sensitive fluorescence in aqueous solution in the blue-green region of the spectrum, with a fluorescence quantum yield of 0.13, and a Polarity Sensitivity Factor (PSF) of 2.0. The utility of this new fluorescent molecule as a probe of supramolecular complexation was demonstrated by its inclusion into the molecular host hydroxypropyl-β-cyclodextrin in aqueous solution. Strictly 1:1 inclusion was observed, with a moderately strong binding constant K of 650 M-1. This new fluorescence probe has significant potential applications in fluorescence-based studies of aqueous biochemical and supramolecular systems.Item Yield of the Fricke dosimeter irradiated with the recoil α and Li ions of the 10B(n,α)7Li nuclear reaction: effects of multiple ionization and temperature(Canadian Science Publishing, 2020-10-25) Zakaria, Abdullah Muhammad; Lertnaisat, Phantira; Islam, Muhammad Mainul; Meesungnoen, Jintana; Katsumura, Yosuke; Jay-Gerin, Jean-PaulMonte Carlo track chemistry simulations were used to investigate the effects of multiple ionization (MI) of water on the yields (G-values) of the ferrous sulfate (Fricke) dosimeter which was irradiated with low-energy α and lithium ion recoils from theItem Simple solvothermal approach to highly nanostructured hematite thin films(Canadian Science Publishing, 2020-09-18) Platnich, Casey M.; Slaby, Jachym; O'Connell, David; Trudel, SimonIn this work, we present a solvothermal method for the synthesis of hematite thin films on fluorine-doped tin oxide substrates. This simple method uses a precursor solution of iron(III) 2,4-pentanedionate dissolved in ethanol with a microliter-scale amount of water and yields hematite ~ 500-nm thick films after annealing. The synthesised films were characterised using an array of methods, including scanning electron microscopy, energy-dispersive X-ray spectroscopy, diffuse reflectance, and powder x-ray diffraction. Incorporating water into the precursor solution provides nucleation sites for the reaction and results show that by altering the amount of water used in the synthesis, it is possible to generate nanocrystalline films of different morphologies, nanocrystal size distributions, and surface areas. This synthetic procedure therefore provides control over the films’ physical and electrochemical characteristics. Doping of hematite thin films is also possible using this synthesis, as exemplified by doping with tin by adding tin(II) 2,4-pentanedionate to the precursor solution. To demonstrate utility, we build prototype photoelectrochemical cells using the synthesized hemtatite as the photoanode.Item Optimizing degradation conditions on treatment of TATB explosive wastewater by γ-Fe2O3 nanoparticles/ UV synergistic degradation(Canadian Science Publishing, 2020-09-14) Liu, Xiaonan; Deng, Yuedan; Zhang, Chaorong; bai, xueyuan; Li, JinshanIn this work, the effect of superparamagnetic γ-Fe2O3 nanoparticles/ ultraviolet light (UV) synergistic degradation on the treatment of 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) explosive wastewater was studied. γ-Fe2O3 nanoparticles were prepared by hydrolysis method and its degradation performance of TATB explosive wastewater was systematically studied with UV light assisted. The results showed that γ-Fe2O3 magnetic nanoparticles have low a size distribution ranged from 5 nm to 10 nm and possesses superparamagnetic properties. The optimized degradation condition was investigated and best degradation performance was obtained with the optimized conditions: the initial of pH=3, UV illumination intensity (5 w/cm2), reaction temperature (25 C), initial TOC concentration (4.025 mg/L) as well as reaction time (60 min). This work can offer a new idea to degrade the explosive wastewater.Item Pan-Canadian Learning Outcomes in Chemistry: A National Snapshot(Canadian Science Publishing, 2020-11-03) Loppnow, Glen R.; Kamau, Patrick; Vergis, ElizabethScience, technology, engineering, and mathematics (STEM) students have, for generations, chosen university Bachelor of Science (B. Sc.) programs for themselves with little or no information about what they may get out of those programs, except as implicitly communicated within the culture and curriculum. However, in Canada, B. Sc. programs typically must explicitly state their program outcomes, at least in their initial submission to their respective provincial ministries of post-secondary education. We undertook a survey of all Canadian institutions’ B. Sc. programs in chemistry to provide a national snapshot of the values and priorities encompassed in institutional delivery of these programs. Our results show a definite preference for knowledge over other learning domains, particularly in translational skills, chemistry, science and the laboratory. Alignment with provincial degree-level expectations, mostly standardized across Canada, is discussed as well.Item Computational investigation of the effect of OH on the hydrogen evolution reaction by Nickel-bis(dithiolene) and Nickel-bis(diselenolene) complexes(Canadian Science Publishing, 2020-10-03) zhang, wenyuan; Lee, Changmin; Bushnell, Eric A.C.In the present study, the reactivity of OH with Ni(X2C2H2)2 and Ni(X2C2H2)2- (where X = S or Se) was investigated From the thermodynamics, it found that the OH radical attacks a backbone C-atom of the Ni(S2C2H2)2 complex. For the Ni(Se2C2H2)2 complex, the OH is predicted to target the ligating chalcogen atom. The significance of this is that with the attack of OH to a backbone C-atom, the thermodynamic cost to lose a proton or hydrogen atom ranges from exergonic to marginally endergonic depending on the oxidation state of the complex. Notably, such a process results in a rearrangement of the complex, likely leading to deactivation of the catalyst. Where OH has attacked a ligating chalcogenide atom, the thermodynamic cost to lose a proton or hydrogen is endergonic regardless of oxidation state of the complex. Where OH attacks a coordinating chalcogenide atom, the thermodynamics for the addition of a proton was considered. At the present level of theory, it was found that for the dithiolene and diselenolene monoanionic complexes, the addition of a proton is marginally endergonic. However, following protonation, the loss of water is significantly exergonic and results in the regeneration of the neutral non-oxidized Ni-complex. Given the greater tendency for OH to attack Se versus S it may be speculated that the use of diselenolene ligands may offer a means to protect the Ni-complex from damaging OH radicals due to the thermodynamic tendency for OH to attack Se atom of the diselenolene complexes not seen in the dithiolene complexes.Item N,N’-Dialkyl-2-Thiobarbituric acid based Sulfonamides as potential SARS-CoV-2 main protease inhibitors(Canadian Science Publishing, 2020-12-31) Sarfraz, Muhammad; Rauf, Abdul; Keller, Paul A; Qureshi, Ashfaq MahmoodAn efficient methodology was developed to avail novel N,N’-dialkyl-2-thiobarbituric acid based sulfonamides S1-S4 in good to excellent yields (84-95%). The synthesized compounds S1-S4 were docked to screen their In-silico activities against two enzymes i.e. SARS-CoV-2 main protease enzyme with unliganded active site (2019-nCoV, coronavirus disease 2019, COVID-19) PDB ID: 6Y84 and SARS-CoV-2 Mpro PDB ID: 6LU7. Furthermore, some In-silico physicochemical and physicokinetic properties were evaluated using OSIRIS property explorer online, molinspiration property calculator, ADMET property calculator and GUSAR to assess these compounds as potential candidates as lead compounds for the quest of SARS- CoV-2 main protease inhibitors. Molecular docking analyses of the synthesized compounds predicted that compound S3 is more potent as SARS-CoV-2 main protease inhibitor with binding energy -11.65 Kcal/mol in comparison to reference inhibitor N3 (-10.95 Kcal/mol), whereas, compounds S1, S2 and S4 recorded comparable binding energies -9.89 Kcal/mol, -10.84 Kcal/mol and -10.94 Kcal/mol with reference inhibitor N3, however much better than remdesivir (-9.85 Kcal/mol). In case of SARS-CoV-2 Mpro, all compounds S1-S4 with docking energy values as -7.28, -8.38, -8.31 and -7.34 Kcal/mol were found potent in comparison to reference inhibitor N3 (-6.31 Kcal/mol) as well as remdesivir (-6.33 Kcal/mol). Ligand efficiency values against the target SARS-CoV-2 proteins as well as α-glucosidase and DNA-(apurinic or apyrimidinic site) lyase inhibition results of these newly synthesized compounds were also found promising.Item Sugars in Space: A Quantum Chemical Study on the Barrierless Formation of Dihydroxyacetone in the Interstellar Medium(Canadian Science Publishing, 2020-10-17) Kong, Aristo; Guljas, Andrea; Csizmadia, Imre G; Fournier, Rene; Fiser, Bela; Rgyanszki, AnitaAmong many theories on the life’s origins, regions between star systems in a galaxy is hypothesized to provide prebiotic material on Earth. Simple sugars, including glycolaldehyde, are confirmed to exist in interstellar medium (ISM) and can be intermediates in the formose reaction to form dihydroxyacetone or DHA. In the studied segment of the formose reaction, hydroxy carbene is sequentially added to formaldehyde, forming glycolaldehyde (hydroxyacetaldehyde) after the first addition and glycerone in the second. The proposed theoretical mechanism was validated through quantum chemical calculations. An exothermic and exergonic pathway favourable in ISM conditions was found, giving a possible explanation for glycerone formation. The products in question participates in biological processes like energy production, the phosphorylated form of glycerone, DHA-P, participates in glycolysis, and energy storage while glycerone is the source of the glycerine backbone in lipids. The studied reaction is a segment of the formose reaction and further polymerization can lead to pentose and hexose, which take part in the formation of RNA and DNA. Hence, this research explores the hypothesis of exogenous production and delivery of prebiotic material to Earth, building up to the conditions allowing the formation of rudimentary lifeforms.Item A QM/MM investigation of the catalytic mechanism of acetylene hydratase: insights into engineering a more effective enzyme(Canadian Science Publishing, 2020-10-03) Zhang, Wenyuan; Bushnell, Eric A.C.In the present investigation, a QM/MM approach was used to better understand the effect of the second environmental shell of the active site on the catalytic conversion of acetylene to acetaldehyde by acetylene hydratase (AH). In addition, the effect of substituting W-coordinating sulfur atoms with selenium atoms was done to provide insight into the influence of the W-coordinating atoms on the catalytic reaction. From the results, it found that the presence of the second shell environment had a significant effect on the reaction. Specifically, in the absence of the MM second shell environment (i.e., QM-cluster model), the rate-determining step is defined by the first proton transfer step. In contrast, for the QM/MM model, the rate-determining step is defined by the water attacking step. Moreover, with the presence of the MM second shell environment, a key intermediate found in the DFT-cluster investigation does not exist in the QM/MM investigation. Rather, what was a two-step process in the DFT-cluster study was calculated to occur in a single step for the QM/MM study. Regarding the sulfur to selenium substitutions, it was found that Gibbs energy for the acetylene binding phase was significantly affected. Notably, the trans-position selenium made the binding of acetylene 65.6 kJ mol−1 less endergonic. Moreover, the overall reaction became 38.2 kJ mol−1 less endergonic compared with the wild type (WT) AH model. Thus, the substitution of key W-coordinating sulfur atoms with selenium atoms may offer a means to enhance the catalytic mechanism of AH considerably.Item Mechanochemistry for sustainable, efficient dehydrogenation/hydrogenation(Canadian Science Publishing, 2020-11-17) Fiss, Blaine G.; Richard, Austin James; Friscic, Tomislav; Moores, AudreyHydrogenation and dehydrogenation reactions are one of the pillars of the chemical industry, with applications from bulk chemicals to pharmaceuticals manufacturing. The ability to selectively add hydrogen across double and (or) triple bonds is key in the chemist’s toolbox and the enabling component in the development of sustainable processes. Traditional solution-based approaches to these reactions are tainted by significant consumption of energy and production of solvent waste. This review highlights the development and applications of recently emerged solvent-free approaches to conduct the hydrogenation of organic molecules using mechanochemistry, i.e., chemical transformations induced or sustained by mechanical force. In particular, we will show mechanochemical techniques such as ball-milling enabled catalytic or stoichiometric metal-mediated hydrogenation and dehydrogenation reactions that are simple, fast, and conducted under significantly milder conditions compared with traditional solution routes. Importantly, we highlight the current challenges and opportunities in this field, while also identifying exciting cases in which mechanochemical hydrogenation strategies lead to new, unique targets and reactivity.Item A simple and efficient metal free, additive, or base free dehydrogenation of tetrahydroisoquinolines using oxygen as a clean oxidant(Canadian Science Publishing, 2020-10-02) Shanmugam, Ramu; Baburaj, BaskarMetal free dehydrogenation of various substituted tetrahydroisoquinolines via a simple and convenient metal free, atom economical route for the synthesis of corresponding isoquinolines under oxygen atmosphere in N-methyl-2-pyrollidone (NMP) is described. Metal free dehydrogenation was carried out without the use of additive or base. A scope of the methodology was demonstrated for a number of aryl and heteroaryl substitutions present at C1 position and ester moiety at C3 position and was found to be good substrates. Substituted isoquinolines (3a–3h) and their esters (3i–3m) were synthesized in very good to excellent yields.