Low temperature, shape-selective formation of Sb2Te3 nanomaterials and their thermoelectric applications

RSC Advances ◽  
2015 ◽  
Vol 5 (109) ◽  
pp. 89621-89634 ◽  
Author(s):  
U. Nithiyanantham ◽  
Sivasankara Rao Ede ◽  
M. Fevzi Ozaydin ◽  
Hong Liang ◽  
A. Rathishkumar ◽  
...  
Keyword(s):  
Reaction Time ◽  
Low Temperature ◽  
Thermoelectric Properties ◽  
Short Reaction Time ◽  
Shape Selective ◽  
Selective Formation

Thermoelectric properties of shape-selective Sb2Te3 nanomaterials which synthesized at a low temperature within a short reaction time have been reported.

Diastereoselective Addition of α-Metalated Sulfoxides to Imines Revisited: Mechanism, Computational Studies, and the Effect of External Chiral Ligands

2003 ◽  
Vol 68 (5) ◽  
pp. 885-898 ◽  
Author(s):  
Brian Pedersen ◽  
Tobias Rein ◽  
Inger Søtofte ◽  
Per-Ola Norrby ◽  
David Tanner
Keyword(s):  
Reaction Time ◽  
Low Temperature ◽  
Asymmetric Synthesis ◽  
Chiral Ligands ◽  
Quantum Mechanical ◽  
Kinetic Control ◽  
Computational Studies ◽  
Quantum Mechanical Calculations ◽  
Short Reaction Time ◽  
Diastereoselective Addition

Some new results on asymmetric synthesis via the addition of α-metalated methyl tolyl sulfoxides to imines are presented. Good diastereoselectivity (up to >98% d.e. for product 3g) can be obtained under conditions of kinetic control (short reaction time, low temperature). The transition state (a six-membered "flat chair") was probed by quantum mechanical calculations, which underpinned the idea of using external chiral ligands to enhance the diastereoselectivity of otherwise moderately selective reactions. In this way, the diastereomeric ratio of the product 3a could be raised from (84:16) to (>99:1) by use of a readily available C2-symmetric bis(sulfonamide) ligand.

Catalyzed Claisen–Schmidt reaction by protonated aluminate mesoporous silica nanomaterial focused on the (E)-chalcone synthesis as a biologically active compound

RSC Advances ◽  
2016 ◽  
Vol 6 (13) ◽  
pp. 11023-11031 ◽  
Author(s):  
Mohammad Reza Sazegar ◽  
Shaya Mahmoudian ◽  
Ali Mahmoudi ◽  
Sugeng Triwahyono ◽  
Aishah Abdul Jalil ◽  
...  
Keyword(s):  
Reaction Time ◽  
Low Temperature ◽  
Mesoporous Silica ◽  
Active Compound ◽  
Biologically Active ◽  
High Yield ◽  
Schmidt Reaction ◽  
Short Reaction Time ◽  
Biologically Active Compound ◽  
Catalyst Reusability

The energy saving HAlMSN catalyzed Claisen–Schmidt reaction for (E)-chalcone synthesis with high yield, low temperature, short reaction time and catalyst reusability.

A Simple Method to Synthese PNIPAM Hydrogel with Improved Response Rate by Conventional Radical Crosslinking Polymerization

2011 ◽  
Vol 236-238 ◽  
pp. 1483-1486
Author(s):  
Qun Feng Liu ◽  
Bo Yuan ◽  
Xiao Feng Chen
Keyword(s):  
Reaction Time ◽  
Low Temperature ◽  
Radical Polymerization ◽  
Response Rate ◽  
Swelling Ratio ◽  
Simple Method ◽  
Short Reaction Time

A kind of poly(N-isopropylacrylamide) (PNIPAM) gel was synthesized by radical polymerization of N-isopropylacrylamide monomer in the present of crosslinker N,N-Methylenebisacylamide using short reaction time. This kind of PNIPAM gel exhibits higher swelling ratio at low temperature and much faster deswelling rate than conventional gel, which could be attributed to the presence of loops, dangling chains and other incomplete structure in the gel caused by short reaction time.

Improved biodiesel manufacture at low temperature and short reaction time

2013 ◽  
Vol 53 ◽  
pp. 242-248 ◽  
Author(s):  
R. Alenezi ◽  
R.C.D. Santos ◽  
S. Raymahasay ◽  
G.A. Leeke
Keyword(s):  
Reaction Time ◽  
Low Temperature ◽  
Short Reaction Time

Tyrosine-Selective Bioconjugation with Iminoxyl Radicals

2020 ◽  
Author(s):  
Katsuya Maruyama ◽  
Takashi Ishiyama ◽  
Yohei Seki ◽  
Kounosuke Oisaki ◽  
Motomu Kanai
Keyword(s):  
Reaction Time ◽  
Steric Hindrance ◽  
Room Temperature ◽  
Water Soluble ◽  
Light Irradiation ◽  
Sodium Ascorbate ◽  
Iminoxyl Radical ◽  
Short Reaction Time ◽  
Modified Peptides ◽  
The Stability

A novel Tyr-selective protein bioconjugation using the water-soluble persistent iminoxyl radical is described. The conjugation proceeded with high Tyr-selectivity and short reaction time under biocompatible conditions (room temperature in buffered media under air). The stability of the conjugates was tunable depending on the steric hindrance of iminoxyl. The presence of sodium ascorbate and/or light irradiation promoted traceless deconjugation, restoring the native Tyr structure. The method is applied to the synthesis of a protein-dye conjugate and further derivatization to azobenzene-modified peptides.

One-Pot, Regioselective Synthesis of Homopropargyl Alcohols using Propargyl Bromide and Carbonyl Compound by the Mg-mediated Reaction under Solvent-free Conditions

2020 ◽  
Vol 17 (6) ◽  
pp. 438-442
Author(s):  
Xiaofang Ma ◽  
Shunxi Li ◽  
Samrat Devaramani ◽  
Guohu Zhao ◽  
Daqian Xu
Keyword(s):  
Reaction Time ◽  
Organic Synthesis ◽  
Carbonyl Compounds ◽  
Solvent Free ◽  
Propargyl Bromide ◽  
Important Goal ◽  
One Pot ◽  
Short Reaction Time ◽  
Solvent Free Conditions ◽  
Volatile Organic

The elimination of volatile organic solvents in organic synthesis is the most important goal in “Green” chemistry. We report a simple, efficient and facile method for the addition of progargyl bromide to carbonyl compounds using Mg metal as a mediator under solvent-free conditions which could regioselectively generate homopropargyl alcohols efficiently in good to excellent yields. The procedure has advantages such as short reaction time, operationally simple, excellent product yields, high regioselectivity and organic solvent-free.

Visible Light Assisted Hantzsch Reaction: Synthesis of Polycyclic Dihydropyridines

2019 ◽  
Vol 16 (8) ◽  
pp. 676-682
Author(s):  
Ankusab Noorahmadsab Nadaf ◽  
Kalegowda Shivashankar
Keyword(s):  
Reaction Time ◽  
Light Intensity ◽  
Ammonium Acetate ◽  
Low Cost ◽  
Aromatic Aldehydes ◽  
Light Irradiation ◽  
High Yield ◽  
Short Reaction Time ◽  
Green Protocol ◽  
Dihydropyridine Derivatives

The polycyclic dihydropyridine nucleus represents the heterocyclic system of invaluable core motifs with wide applications in chemical, biological and physical properties. Although this kind of compounds have been extensively synthesized by other groups, the synthesis of these compounds under CFL light intensity were not explored. The synthesis of polycyclic dihydropyridine derivatives were achieved through the reaction of 4-hydroxycoumarin, aromatic aldehydes and ammonium acetate under CFL light irradiation conditions. A series of polycyclic dihydropyridine derivatives were prepared under CFL light irradiation conditions with high yield, short reaction time, ambient condition and without the use of catalyst. The results displayed an efficient method for the synthesis of polycyclic dihydropyridine derivatives. Clean profile, short reaction time, low cost and use of CFL light intensity instead of catalyst making it a genuinely green protocol.

Alumina-K3PO4 Solid Supported Microwave Synthesis of 1, 3-diaryl-2- propene-1-one Derivatives as a Prominent Antioxidant Scavenger

2020 ◽  
Vol 7 (2) ◽  
pp. 145-156
Author(s):  
Pravinkumar Patil ◽  
Gangadhar Bhopalkar ◽  
Sainath Zangade
Keyword(s):  
Antioxidant Activity ◽  
Reaction Time ◽  
Microwave Irradiation ◽  
Spectral Studies ◽  
Hydroxy Derivative ◽  
Scavenging Activity ◽  
Short Reaction Time ◽  
Basic Alumina ◽  
Ic50 Value ◽  
Nitric Oxide Radical

Background: The various industrial processes have a diverse effect on the environment through pollution. In view of these observations, some environmentally benign synthetically protocols have developed under green chemistry. For rapid and sustainable synthesis, the microwave irradiation (MI) has gained popularity as a powerful tool compared to conventional synthesis. The present study describes the synthesis of novel substituted 1, 3-diaryl-2-propene-1-one derivative using alumina supported K3PO4-MWI combination. Objective: Chalcones are important compounds which are widely spread in nature like in fruits, vegetables, tea, spices, etc. The 2’-hydroxy derivative of chalcones plays an important role in the synthesis of bioactive compounds. The present communication deals with a convenient and rapid synthesis of 1, 3-diaryl-2-propene-1-one under the support of alumina-tripotassium phosphate and microwave irradiation. Our efforts are focused on the introduction of typical and easier route for the synthesis of title compounds using a microwave. All synthesized chalcones have been screened and evaluated for the antioxidant activity by DPPH and nitric oxide radical scavenging. Some of these compounds are found to be more potent scavengers and may lead to the development of a new class of antioxidants. Methods: The α, β-unsaturated carbonyl functionality contains two electrophilic centers allowing them to undergo addition and cyclization reactions with different nucleophiles. In the literature survey, we found that Chalcones were synthesized using tripotassium phosphate catalyst under refluxing by a conventional method. A novel method for the synthesis of 1, 3-diaryl-2-propene-1-one via Claisen Schmidt has been introduced by reacting substituted 2’- hydroxyl acetonaphthones with substituted aromatic aldehydes under the support of basic alumina –tripotassium phosphate via microwave radiations. Formation of corresponding Chalcones was confirmed by spectral studies followed by their screening for antioxidant activity. The scavenging activity is expressed in terms of % inhibition and IC50 value (μg/ml). Results: The structures of newly synthesized Chalcones were confirmed and in good agreement with obtained spectral analysis such as IR, NMR, Mass and elemental analysis. Commercially available basic alumina and tripotassium phosphate in combination of microwave were utilized and found to be effective, convenient route for the synthesis of 1, 3-diaryl-2-propene-1-one derivatives with desirable yields in short reaction time (5-12 min). The results of antioxidant activity revealed that the IC50 value for compounds 3a, 3d, 3e, 3f, 3g, 3h, 3j, 3l and 3n are lower than that of standard ascorbic acid to scavenge DPPH radical. This indicates that these compounds are more significant scavengers in comparison with standard drug. On the other hand, compounds 3a, 3b, 3c, 3d, 3g, 3l and 3n are more potent scavengers for NO free radical. Conclusion: We have introduced an efficient, ecofriendly, simple and fast microwave assisted method using basic alumina-tripotassium phosphate for the synthesis of 1, 3-diaryl-2-propene-1- one derivatives. Microwave irradiation provides an effective way for the preparation of Chalcones in terms of several advantages as a simple procedure, short reaction time, milder reaction condition, cleaner reaction and excellent yield. The scavenging activity of chalcones against DPPH and NO free radicals showed excellent properties of antioxidants.

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