Supported metals on porous solids as heterogeneous catalysts for the synthesis of propargylamines

2022 ◽  
Author(s):  
Francisco G. Cirujano ◽  
Amarajothi Dhakshinamoorthy
Keyword(s):  
Heterogeneous Catalysts ◽  
Porous Solids ◽  
Drug Molecules ◽  
Target Molecules ◽  
Supported Metals ◽  
High Yields ◽  
Very High

Propargylamines are one of the aza-compounds very often observed in many drug molecules. Hence, considerable efforts have been made to obtain these target molecules in very high yields and selectivity....

The Synthesis and Application of Functionalized Mesoporous Silica SBA-15 as Heterogeneous Catalyst in Organic Synthesis

2020 ◽  
Vol 24 ◽  
Author(s):  
Ghodsi Mohammadi Ziarani ◽  
Shima Roshankar ◽  
Fatemeh Mohajer ◽  
Alireza Badiei
Keyword(s):  
Mesoporous Silica ◽  
Heterogeneous Catalyst ◽  
Organic Synthesis ◽  
Lewis Acid ◽  
Heterogeneous Catalysts ◽  
Organic Transformations ◽  
Functionalized Mesoporous Silica ◽  
Silica Nanomaterials ◽  
Wide Range ◽  
Target Molecules

Abstract:: Mesoporous silica nanomaterials provide an extraordinary advantage for making new and superior heterogeneous catalysts because of their surface silanol groups. The functionalized mesoporous SBA-15, such as acidic, basic, BrÖnsted, lewis acid, and chiral catalysts, are used for a wide range of organic synthesis. The importance of the chiral ligands, which were immobilized on the SBA-15, was mentioned in this review to achieve chiral products as valuable target molecules. Herein, their synthesis and application in different organic transformations are reviewed from 2016 till date 2020.

scholarly journals Multi-curie production of gallium-68 on a biomedical cyclotron and automated radiolabelling of PSMA-11 and DOTATATE

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Helge Thisgaard ◽  
Joel Kumlin ◽  
Niels Langkjær ◽  
Jansen Chua ◽  
Brian Hook ◽  
...  
Keyword(s):  
Radiochemical Purity ◽  
High Yield ◽  
Clinical Use ◽  
Automated Production ◽  
Automated Method ◽  
Gallium 68 ◽  
High Yields ◽  
High Level ◽  
Mev Protons ◽  
Very High

Abstract Background With increasing clinical demand for gallium-68, commercial germanium-68/gallium-68 ([68Ge]Ge/[68Ga]Ga) generators are incapable of supplying sufficient amounts of the short-lived daughter isotope. In this study, we demonstrate a high-yield, automated method for producing multi-Curie levels of [68Ga]GaCl3 from solid zinc-68 targets and subsequent labelling to produce clinical-grade [68Ga]Ga-PSMA-11 and [68Ga]Ga-DOTATATE. Results Enriched zinc-68 targets were irradiated at up to 80 µA with 13 MeV protons for 120 min; repeatedly producing up to 194 GBq (5.24 Ci) of purified gallium-68 in the form of [68Ga]GaCl3 at the end of purification (EOP) from an expected > 370 GBq (> 10 Ci) at end of bombardment. A fully automated dissolution/separation process was completed in 35 min. Isolated product was analysed according to the Ph. Eur. monograph for accelerator produced [68Ga]GaCl3 and found to comply with all specifications. In every instance, the radiochemical purity exceeded 99.9% and importantly, the radionuclidic purity was sufficient to allow for a shelf-life of up to 7 h based on this metric alone. Fully automated production of up to 72.2 GBq [68Ga]Ga-PSMA-11 was performed, providing a product with high radiochemical purity (> 98.2%) and very high apparent molar activities of up to 722 MBq/nmol. Further, manual radiolabelling of up to 3.2 GBq DOTATATE was performed in high yields (> 95%) and with apparent molar activities (9–25 MBq/nmol) sufficient for clinical use. Conclusions We have developed a high-yielding, automated method for the production of very high amounts of [68Ga]GaCl3, sufficient to supply proximal radiopharmacies. The reported method led to record-high purified gallium-68 activities (194 GBq at end of purification) and subsequent labelling of PSMA-11 and DOTATATE. The process was highly automated from irradiation through to formulation of the product, and as such comprised a high level of radiation protection. The quality control results obtained for both [68Ga]GaCl3 for radiolabelling and [68Ga]Ga-PSMA-11 are promising for clinical use.

scholarly journals Premium biofuels from straw – production of advanced biofuels using the Sylvan process

Paliva ◽  
2020 ◽  
pp. 87-92
Author(s):  
Jaroslav Aubrecht ◽  
David Kubička
Keyword(s):  
Heterogeneous Catalysts ◽  
Cetane Number ◽  
Reaction Products ◽  
Advanced Biofuels ◽  
Transportation Fuels ◽  
Noble Metal Catalysts ◽  
Eu Directive ◽  
Increasing Demand ◽  
High Yields ◽  
Middle Distillates

The increasing demand for transportation fuels, especially middle distillates, stimulates the research of new strategies to obtain or synthesize biofuels. The processing of lignocellulosic biomass (for example straw) is a process of great interest, because after its hydrolysis and subsequent dehydration of the resulting sugar monomers, very valuable substances including furfural are obtained. Then, furfural is selectively hydrogenated to 2-methylfuran, sylvan, that is the basic “building block” in the Sylvan process. This manuscript summarizes the knowledge on Sylvan process as a promising way of biofuels synthesis. By sylvan condensing with aldehydes, ketones or even 2-methylfuran itself, it is possible to prepare C13-C16 oxygenates in high yields up to 100 % under mild reaction conditions (30 - 60 °C) over various heterogeneous catalysts. Based on the overview, the heterogeneous catalysts are preferred and the immobilized sulfonic acids are the most active catalysts, however, expensive. The reaction products then may be hydrodeoxygenated commonly over supported noble metal catalysts to provide premium quality C13-C16 hydrocarbons to produce diesel or kerosene. These fractions have great low-temperature properties such as CFPP (-50 °C) or cetane number (70-72). According to the proposed sustainability prediction, this process could be sustainable in the Czech Republic, where 30 % of produced wheat straw could be used for the production of 130 kt advanced biofuels by Sylvan process required by EU directive RED II. Finally, the future approaches have been suggested.

Reductions with sulfurated borohydrides. V. Reductions of ketones

1970 ◽  
Vol 48 (15) ◽  
pp. 2366-2371 ◽  
Author(s):  
J. M. Lalancette ◽  
A. Freche
Keyword(s):  
High Temperature ◽  
Carbonyl Group ◽  
Sodium Borohydride ◽  
Room Temperature ◽  
High Yield ◽  
High Yields ◽  
Very High

Ketones can be reduced with sulfurated sodium borohydride. Very high yield (≈90%) of the corresponding alcohol is obtained with the appropriate ratio of ketone and hydride at room temperature. The reaction is much influenced by the steric environment around the carbonyl group. At high temperature (65°) disulfides and tetrasulfides are produced. In some cases the structure of those sulfides have been established. Conjugated ketones can be reduced to the corresponding alcohols with very high yields.

scholarly journals Copper nanoparticles on controlled pore glass (CPG) as highly efficient heterogeneous catalysts for “click reactions”

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Abdolrahim A. Rafi ◽  
Ismail Ibrahem ◽  
Armando Córdova
Keyword(s):  
Copper Nanoparticles ◽  
Heterogeneous Catalysts ◽  
Catalyst System ◽  
Terminal Alkynes ◽  
Click Reactions ◽  
Dipolar Cycloadditions ◽  
Organic Azides ◽  
Controlled Pore Glass ◽  
Pore Glass ◽  
High Yields

AbstractWe herein report that supported copper nanoparticles (CuNPs) on commercially available controlled pore glass (CPG), which exhibit high mechanical, thermal and chemical stability as compared to other silica-based materials, serve as a useful heterogeneous catalyst system for 1,3-dipolar cycloadditions (“click” reactions) between terminal alkynes and organic azides under green chemistry conditions. The supported CuNPs-CPG catalyst exhibited a broad substrate scope and gave the corresponding triazole products in high yields. The CuNPs-CPG catalyst exhibit recyclability and could be reuced multiple times without contaminating the products with Cu.

Effect of base on alkyltriphenylphosphonium salts in polar aprotic solvents

2008 ◽  
Vol 86 (7) ◽  
pp. 668-675 ◽  
Author(s):  
Julius N Ngwendson ◽  
Cassandra M Schultze ◽  
Jordan W Bollinger ◽  
Anamitro Banerjee
Keyword(s):  
Phosphonium Salt ◽  
Phenyl Group ◽  
Aprotic Solvents ◽  
Phosphonium Salts ◽  
Bromide Form ◽  
Mechanistic Investigation ◽  
High Yields ◽  
Excess Base ◽  
Homocoupling Reaction ◽  
Very High

When arylmethyl phosphonium salts are treated with a base (e.g., t-BuOK or NaH) they homocouple to form symmetric 1,2-diarylethenes. In some cases, dilution and (or) use of excess base lead to very high yields of the product. This reaction is solvent sensitive: the reaction occurs only when polar aprotic solvents such as acetonitrile or DMSO are used. Other alkyl phosphonium salts (e.g., ethoxycarbonylmethyltriphenylphosphonium bromide and n-butyltriphenylphosphonium bromide) form a ylid (when an α-carbonyl group is present) or lose a phenyl group to form alkyldiphenylphosphine oxides when treated with the base. Mechanistic investigation of the homocoupling reaction indicates that the reaction proceeds through a ylid that acts as a nucleophile on an unreacted phosphonium salt. The resulting adduct undergoes elimination to form the observed product. The E/Z ratio seems to depend on the amount of the base used and the phosphonium salt involved.Key words: phosphonium salts, homocoupling, 1,2-diarylalkene, Ylids.

scholarly journals An Efficient and Recycling Catalyst for the One-Pot Three-Component Synthesis of Substituted 3,4-Dihydropyrimidin-2(1H)-ones

2008 ◽  
Vol 5 (4) ◽  
pp. 688-695 ◽  
Author(s):  
Taoues Boumoud ◽  
Boudjemaa Boumoud ◽  
Salah Rhouati ◽  
Ali Belfaitah ◽  
Abdelmadjid Debache ◽  
...  
Keyword(s):  
Reaction Times ◽  
Aromatic Aldehydes ◽  
One Pot ◽  
First Derivative ◽  
Target Molecules ◽  
The One ◽  
High Yields

The Biginelli one-pot three-component cyclocondensation was applied in this work to prepare 3,4-dihydropyrimidinone and its analogues using the first derivative of lead, Pb(NO3)2, as a recycling catalyst, from a diversity of aromatic aldehydes, β-ketoesters and urea. The reaction was carried out in refluxing acetonitrile and afforded the target molecules in good to excellent yields. The method offers several advantages including high yields of the products, short reaction times and easy experimental workup procedure

scholarly journals New Uncharged 2-Thienostilbene Oximes as Reactivators of Organophosphate-Inhibited Cholinesterases

2021 ◽  
Vol 14 (11) ◽  
pp. 1147
Author(s):  
Milena Mlakić ◽  
Tena Čadež ◽  
Danijela Barić ◽  
Ivana Puček ◽  
Ana Ratković ◽  
...  
Keyword(s):  
Docking Studies ◽  
New Class ◽  
Nerve Signal ◽  
Central Nervous Systems ◽  
Cns Activity ◽  
High Yields ◽  
Further Development ◽  
The Brain ◽  
Very High ◽  
Inhibited Enzyme

The inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) by organophosphates (OPs) as nerve agents and pesticides compromises normal cholinergic nerve signal transduction in the peripheral and central nervous systems (CNS) leading to cholinergic crisis. The treatment comprises an antimuscarinic drug and an oxime reactivator of the inhibited enzyme. Oximes in use have quaternary nitrogens, and therefore poorly cross the brain–blood barrier. In this work, we synthesized novel uncharged thienostilbene oximes by the Wittig reaction, converted to aldehydes by Vilsmeier formylation, and transformed to the corresponding uncharged oximes in very high yields. Eight trans,anti- and trans,syn-isomers of oximes were tested as reactivators of nerve-agent-inhibited AChE and BChE. Four derivatives reactivated cyclosarin-inhibited BChE up to 70% in two hours of reactivation, and docking studies confirmed their productive interactions with the active site of cyclosarin-inhibited BChE. Based on the moderate binding affinity of both AChE and BChE for all selected oximes, and in silico evaluated ADME properties regarding lipophilicity and CNS activity, these compounds present a new class of oximes with the potential for further development of CNS-active therapeutics in OP poisoning.

scholarly journals Multi-Curie Production of Gallium-68 on a Biomedical Cyclotron and Automated Radiolabelling of PSMA-11 and DOTATATE

2020 ◽  
Author(s):  
Helge Thisgaard ◽  
Joel Kumlin ◽  
Niels Langkjær ◽  
Jansen Chua ◽  
Brian Hook ◽  
...  
Keyword(s):  
Radiochemical Purity ◽  
High Yield ◽  
Clinical Use ◽  
Automated Production ◽  
Automated Method ◽  
Gallium 68 ◽  
High Yields ◽  
High Level ◽  
Mev Protons ◽  
Very High

Abstract Background: With increasing clinical demand for gallium-68, commercial germanium-68/gallium-68 ([68Ge]Ge/[68Ga]Ga) generators are incapable of supplying sufficient amounts of the short-lived daughter isotope. In this study, we demonstrate a high-yield, automated method for producing multi-Curie levels of [68Ga]GaCl3 from solid zinc-68 targets and subsequent labelling to produce clinical-grade [68Ga]Ga-PSMA-11 and [68Ga]Ga-DOTATATE.Results: Enriched zinc-68 targets were irradiated at up to 80 µA with 13 MeV protons for 120 min; repeatedly producing up to 194 GBq (5.24 Ci) of purified gallium-68 in the form of [68Ga]GaCl3 at the end of purification (EOP) from an expected >370 GBq (>10 Ci) at end of bombardment. A fully automated dissolution/separation process was completed in 35 min. Isolated product was analysed according to the draft Ph. Eur. monograph for accelerator produced [68Ga]GaCl3 and found to comply with all specifications. In every instance, the radiochemical purity exceeded 99.9% and importantly, the radionuclidic purity was sufficient to allow for a shelf-life of up to 7 h based on this metric alone. Fully automated production of up to 72.2 GBq [68Ga]Ga-PSMA-11 was performed, providing a product with high radiochemical purity (>98.2%) and very high apparent molar activities of up to 722 MBq/nmol. Further, manual radiolabelling of up to 3.2 GBq DOTATATE was performed in high yields (>95%) and with apparent molar activities (9-25 MBq/nmol) sufficient for clinical use.Conclusions: We have developed a high-yielding, automated method for the production of very high amounts of [68Ga]GaCl3, sufficient for supply proximal radiopharmacies. The reported method led to record-high purified gallium-68 activities (194 GBq at end of purification) and subsequent labelling of PSMA-11 and DOTATATE. The process was highly automated from irradiation through to formulation of the product, and as such comprised a high level of radiation protection. The quality control results obtained for both [68Ga]GaCl3 for radiolabelling and [68Ga]Ga-PSMA-11 are promising for clinical use.

Assessment of shallot collection accessions in breeding for yield capacity

2018 ◽  
pp. 58-66
Author(s):  
O.N. Bilenka
Keyword(s):  
The Netherlands ◽  
High Resistance ◽  
Practical Interest ◽  
Viral Diseases ◽  
Economic Traits ◽  
Breeding Programs ◽  
Yield Capacity ◽  
High Yields ◽  
Very High ◽  
Bulb Yield

Goal. To evaluation of the shallot gene pool for bulb yield and its components, resistance to viral diseases and to select the most valuable accessions for breeding programs. Results and Discussion. The article presents the results of evaluating 25 shallot accessions for yield and resistance to viral diseases. Five accessions with very high bulb yields (> 135% related to the standard) were selected from the following regions of Ukraine (from the Dnipropetrovska region - D-135 (13.1 t/ha); from the Poltavska region - D-127 (13.9 t/ha); from the Kharkivska region - D-15 (14.0 t/ha), D-34 (14.9 t/ha)) and from the Netherlands (Bonilla (15.9 t/ha). Accessions with high yields (116 - 135% related to the standard) were from the Dnipropetrovska region (D-136 (11.2 t/ha), varieties Olviia (12.3 t/ha) and Kushchyovka Kharkovskaya (12.6 t/ha). Ten accessions were the best in terms of bulb weight, exceeding the standard by 3.0 - 8.3 g:- D-33 (14.2 g), Olviia (14.5 g), D-4 (14.7 g), D- 133 (15.1 g), D-137 (15.2 g), D-130 (15.7 g), D-127 (15.9 g), D-15 (16.6 g), D- 34 (18.3 g), and Bonilla (19.5 g). Seven accessions were noticeable for the bulb number per bulb stem: from the Dnipropetrovska region (D-136 (6.1 bulbs), D-123 (7.0 bulbs), D-124 (7.4 bulbs), D-135 (7.4 bulbs), D-137 (6.4 bulbs), and D-129 (8.0 bulbs)) and from the Netherlands (Bonilla (6.1 bulbs). The following accessions were distinguished by resistance to viral diseases (onion yellow dwarf and mosaic) as sources for breeding: with very high resistance (9 points) - D-120 from Russia, 12 accessions with high resistance (7 points) from Ukraine (D- 4, D-26, D-136, D-125, D-127, D-133, D-130, D-123, D-126, D-137, and D-140) and Bonilla from the Netherlands. Accessions D-127 (Poltavska region), D-137 (Dnipropetrovska region), D-34 and D-15 (Kharkivska region), Bonilla (Netherlands) with a set of traits are of practical interest for breeding. Conclusions. Having studied 25 shallot collection accessions in 2016 – 2018, we distinguished the following accessions: by bulb yield - 8 accessions (11.7 - 15.9 t/ha), by bulb weight - 10 accessions (14.2 - 18.3 g), by the bulb number per bulb stem - 7 accessions (6.1 – 8.0 bulbs), by resistance to viral diseases - 13 accessions (7 – 9 points), by a set of valuable economic traits – 5 accessions.

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