Theoretical insights into boron reducing agent for the reduction of carbonyl compounds

2021 ◽  
Author(s):  
Nana Ma ◽  
Qingli Xu ◽  
Guisheng Zhang
Keyword(s):  
Carbonyl Compounds ◽  
Catalytic Reduction ◽  
Reducing Agents ◽  
Reducing Agent ◽  
Reduction Reactions

In this perspective we present computational progress in the reduction of carbonyl compounds using boron reducing agents such as L∙BH3, HBcat, HBpin and 9-BBN. For the catalytic reduction reactions, the...

scholarly journals Reduction of Carbonyl Compounds to Their Corresponding Alcohols by (Nicotine)(tetrahydroborato)zinc Complex as a New Stable and Efficient Reducing Agent

2012 ◽  
Vol 9 (4) ◽  
pp. 2338-2345 ◽  
Author(s):  
Davood Setamdideh ◽  
Mostafa Rafigh
Keyword(s):  
Carbonyl Compounds ◽  
Room Temperature ◽  
Zinc Complex ◽  
Reducing Agent ◽  
Reduction Reactions

(Nicotine)(tetrahydroborato)zinc complex, [Zn(BH4)2(nic)], as a stable yellow solid, was prepared quantitatively by complexation of an equimolar amounts of zinc tetrahydroborate and Nicotine at room temperature. This reagent can easily reduce variety of carbonyl compounds such as aldehydes, ketones, acyloins and α-diketones to their corresponding alcohols in good to excellent yields. Reduction reactions were performed in CH3CN at room temperature.

scholarly journals The Influence of Water Reducing Agents on Early Hydration Property of Ferrite Aluminate Cement Paste

Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 731
Author(s):  
Chunlong Huang ◽  
Zirui Cheng ◽  
Jihui Zhao ◽  
Yiren Wang ◽  
Jie Pang
Keyword(s):  
Setting Time ◽  
Critical Role ◽  
Hydration Product ◽  
Reducing Agents ◽  
Reducing Agent ◽  
Hydration Process ◽  
Early Hydration ◽  
Cement Pastes ◽  
Hydration Rate ◽  
Aluminate Cement

The ferrite aluminate cement (FAC) could rapidly lose fluidity or workability due to its excessive hydration rate, and greatly reduce the construction performance. Chemical admixtures are commonly used to provide the workability of cement-based materials. In this study, to ensure required fluidity of FAC, chemically different water reducing agents are incorporated into the FAC pastes. The experiments are performed with aliphatic water reducing agent (AP), polycarboxylic acid water reducing agent (PC) and melamine water reducing agent (MA), respectively. Influence of the water reducing agents on fluidity, setting time, hydration process, hydration product and zeta potential of the fresh cement pastes is investigated. The results show that PC has a better dispersion capacity compared to AP and MA. Besides decreasing water dosage, PC also acts as a retarder, significantly increasing the setting times, delaying the hydration rate and leading to less ettringite in the hydration process of FAC particles. The water reducing agents molecules are adsorbed on the surface of positively charged minerals and hydration products, however, for PC, steric hindrance from the long side chain of PC plays a critical role in dispersing cement particles, whereas AP and MA acting through an electrostatic repulsion force.

Sodium borohydride: A versatile reagent in the reductive N-monoalkylation of α-amino acids and α-amino methyl esters

2002 ◽  
Vol 80 (7) ◽  
pp. 779-788 ◽  
Author(s):  
Giancarlo Verardo ◽  
Paola Geatti ◽  
Elena Pol ◽  
Angelo G Giumanini
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Sodium Borohydride ◽  
Carbonyl Compounds ◽  
Condensation Reaction ◽  
Methyl Esters ◽  
Reducing Agent ◽  
Reductive Condensation ◽  
Versatile Reagent

α-Amino acids and α-amino methyl esters are easily converted to their N-monoalkyl derivatives by a reductive condensation reaction using several carbonyl compounds in the presence of sodium borohydride. This reducing agent has shown a wide versatility with minor but essential procedural variations. The reaction allows the α-monodeuterium labeling of the new N-substituent by use of sodium borodeuteride.Key words: α-amino acid, α-amino methyl esters, sodium borohydride, reductive N-monoalkylation, carbonyl compounds.

scholarly journals Poly(N-isopropylacrylamide-co-methacrylic acid) microgel stabilized copper nanoparticles for catalytic reduction of nitrobenzene

2015 ◽  
Vol 33 (3) ◽  
pp. 627-634 ◽  
Author(s):  
Zahoor H. Farooqi ◽  
Zonarah Butt ◽  
Robina Begum ◽  
Shanza Rhauf Khan ◽  
Ahsan Sharif ◽  
...  
Keyword(s):  
Copper Nanoparticles ◽  
Methacrylic Acid ◽  
Catalytic Reduction ◽  
Aqueous Media ◽  
Activation Parameters ◽  
Reducing Agent ◽  
Different Temperatures ◽  
Entropy Of Activation ◽  
Micro Reactors

Abstract Poly(N-isopropylacrylamide-co-methacrylic acid) microgels [p(NIPAM-co-MAAc)] were synthesized by precipitation polymerization of N-isopropylacrylamide and methacrylic acid in aqueous medium. These microgels were characterized by dynamic light scattering and Fourier transform infrared spectroscopy. These microgels were used as micro-reactors for in situ synthesis of copper nanoparticles using sodium borohydride (NaBH4) as reducing agent. The hybrid microgels were used as catalysts for the reduction of nitrobenzene in aqueous media. The reaction was performed with different concentrations of cat­alyst and reducing agent. A linear relationship was found between apparent rate constant (kapp) and amount of catalyst. When the amount of catalyst was increased from 0.13 to 0.76 mg/mL then kapp was increased from 0.03 to 0.14 min-1. Activation parameters were also determined by performing reaction at two different temperatures. The catalytic process has been discussed in terms of energy of activation, enthalpy of activation and entropy of activation. The synthesized particles were found to be stable even after 14 weeks and showed catalytic activity for the reduction of nitrobenzene.

An unsaturated metal site-promoted approach to construct strongly coupled noble metal/HNb3O8 nanosheets for efficient thermo/photo-catalytic reduction

Nanoscale ◽  
2017 ◽  
Vol 9 (38) ◽  
pp. 14654-14663 ◽  
Author(s):  
Lijuan Shen ◽  
Yuzhou Xia ◽  
Sen Lin ◽  
Shijing Liang ◽  
Ling Wu
Keyword(s):  
Noble Metal ◽  
Catalytic Reduction ◽  
Reducing Agent ◽  
Capping Agent ◽  
Strongly Coupled ◽  
Metal Site

A Nb4+-promoted approach has been developed to construct Pd/HNb3O8 without a reducing agent or a capping agent. The resulting composites function as efficient thermo/photo-catalysts.

scholarly journals Synthesis of Gold Nanoparticles Using p-Aminobenzoic Acid and p-Aminosalicylic Acid as Reducing Agent

2019 ◽  
Vol 19 (1) ◽  
pp. 68
Author(s):  
Abdul Aji ◽  
Eko Sri Kunarti ◽  
Sri Juari Santosa
Keyword(s):  
Gold Nanoparticles ◽  
Optimum Condition ◽  
Reducing Agents ◽  
Reducing Agent ◽  
Hydroxyl Group ◽  
Synthesis Process ◽  
Aminobenzoic Acid ◽  
Aminosalicylic Acid ◽  
Amino Groups ◽  
Transmission Electron

Synthesis of gold nanoparticles (AuNPs) by reduction of HAuCl4 with p-aminobenzoic acid and p-aminosalicylic acid as a reducing agent was investigated. This work was conducted in order to determine the optimum condition of AuNPs synthesis and examine the effect of the hydroxyl group in p-aminosalicylic acid towards the size, shape, and stability of the synthesized gold nanoparticles (AuNPs). The optimum condition of the gold nanoparticles synthesis was determined by UV/Vis spectrophotometer, the shape and size of gold nanoparticles were measured by Transmission Electron Microscope (TEM). The synthesis process was started by reacting HAuCl4 and the reducing agents in an aqueous solution at 86 ºC. The initial gold concentration, reducing agents concentration and pH were varied in order to obtain the optimum condition. In the optimum condition, the results showed that p-aminosalicylic acid containing both hydroxyl and amino groups performed higher reduction ability compared to p-aminobenzoic acid that only containing an amino group. Reducing agents which have a hydroxyl group (p-aminosalicylic acid) could produce AuNPs with a smaller concentration of HAuCl4 than p-aminobenzoic acid. Gold nanoparticles that were synthesized with p-aminosalicylic acid were more stable and had a smaller particle size compared to its counterpart that is synthesized with p-aminobenzoic acid.

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