Amphiphilic Biaryl Monophosphine Ligands by Regioselective Sulfonation

10.26434/chemrxiv.13337471 ◽

2020 ◽

Author(s):

Jacob Rodriguez ◽

Heemal Dhanjee ◽

Stephen L. Buchwald

Keyword(s):

Sulfuric Acid ◽

Chromatographic Purification ◽

Organometallic Reactions ◽

One Step ◽

High Yields

<div> <p>Amphiphilic ligands are valued for their ability to facilitate organometallic reactions in the presence of water. The regioselective sulfonation of a series of commercially available biaryl monophosphines to generate amphiphilic ligands is presented. In this one-step protocol, the temperature and addition of fuming sulfuric acid were carefully controlled to arrive at sulfonated biaryl monophosphine ligands in high yields with >95% regioselectivity without the need for chromatographic purification.</p> </div>

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PEG-embedded KBr3: A recyclable catalyst for multicomponent coupling reaction for the efficient synthesis of functionalized piperidines

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.7.157 ◽

2011 ◽

Vol 7 ◽

pp. 1334-1341 ◽

Cited By ~ 29

Author(s):

Sanny Verma ◽

Suman L Jain ◽

Bir Sain

Keyword(s):

Coupling Reaction ◽

Recyclable Catalyst ◽

Efficient Synthesis ◽

Molecular Bromine ◽

Keto Ester ◽

One Step ◽

High Yields ◽

Multicomponent Coupling ◽

Three Component Coupling

PEG-embedded potassium tribromide ([K+PEG]Br3 −) was found to be an efficient and recyclable catalyst for the synthesis of functionalized piperidines in high yields in a one step, three component coupling between aldehyde, amine and β-keto ester. At the end of the reaction the [K+PEG]Br3 − was readily regenerated from the reaction mixture by treating the residue containing [K+PEG]Br− with molecular bromine.

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Study of Carbohydrate Hydrolysis From Arracacha Roots (Arracacia Xanthorriza Bancroft) to Produce Fermentable Sugars

Ingeniería e Investigación ◽

10.15446/ing.investig.v41n2.87365 ◽

2021 ◽

Vol 41 (2) ◽

pp. e87365

Author(s):

Darwin Carranza Saavedra ◽

Jorge Andrés Alvarado Nuñez ◽

José Fernando Solanilla Duque ◽

Claudia Patricia Valenzuela Real

Keyword(s):

Acetic Acid ◽

Sulfuric Acid ◽

Mechanical Damage ◽

Maximum Level ◽

Raw Material ◽

Saturated Steam ◽

Fermentation Inhibitors ◽

Carbohydrate Hydrolysis ◽

Fermentable Carbohydrates ◽

High Yields

In Colombia, approximately 855 840 tons of arracacha are produced each year. The unsalable postharvest arracacha root (Arracacia xanthorriza Bancroft) is not commercialized, mainly due to mechanical damage or small and misshapen roots. In this work, dry samples were characterized and subjected to two treatments: one using thermal hydrolysis, applying saturated steam at pressures of 0,1034 MPa, 0,2068 MPa, and 0,4137 MPa; and another one using hydrolysis with sulfuric acid in concentrations between 0,252,00 M. Then, the cake resulting from the hydrolysis and filtration process was enzymatically hydrolyzed (Liquozyme SC DS, Novozymes) at 1,5, 5 and 10 KNU/g (pH 6, 80 _C, 2 h). Fermentation inhibitors (acetic acid and furfural) were evaluated in the best pretreatment. The results showed that the treatment with sulfuric acid at 1,00 M (2 h) has high yields in reducing sugars added to enzymatic hydrolysis. The maximum level of fermentable carbohydrates per gram of dry sample (1,04 g/g) was also reached. Regarding the fermentation inhibitors of the reducing sugar, a higher concentration of acetic acid was found with a lower furfural content. Therefore, arracacha discards are a promising raw material to increase the supply of bioethanol.

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New palladium–oxazoline complexes: Synthesis and evaluation of the optical properties and the catalytic power during the oxidation of textile dyes

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.11.132 ◽

2015 ◽

Vol 11 ◽

pp. 1175-1186 ◽

Cited By ~ 6

Author(s):

Rym Hassani ◽

Mahjoub Jabli ◽

Yakdhane Kacem ◽

Jérôme Marrot ◽

Damien Prim ◽

...

Keyword(s):

Optical Properties ◽

Spectroscopic Analysis ◽

Palladium Complexes ◽

X Ray Diffraction ◽

Factors Affecting ◽

Enantiomerically Pure ◽

One Step ◽

Uv Visible ◽

High Yields

The present paper describes the synthesis of new palladium–oxazoline complexes in one step with good to high yields (68–95%). The oxazolines were prepared from enantiomerically pure α-aminoalcohols. The structures of the synthesized palladium complexes were confirmed by NMR, FTIR, TOFMS, UV–visible spectroscopic analysis and X–ray diffraction. The optical properties of the complexes were evaluated by the determination of the gap energy values (E g) ranging between 2.34 and 3.21 eV. Their catalytic activities were tested for the degradation of Eriochrome Blue Black B (a model of azo dyes) in the presence of an ecological oxidant (H2O2). The efficiency of the decolorization has been confirmed via UV–visible spectroscopic analysis and the factors affecting the degradation phenomenon have been studied. The removal of the Eriochrome reached high yields. We have found that the complex 9 promoted 84% of color elimination within 5 min (C 0 = 30 mg/L, T = 22 °C, pH 7, H2O2 = 0.5 mL) and the energetic parameters have been also determined.

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Silica sulfuric acid magnetic nanoparticle: an efficient and ecofriendly catalyst for synthesis of spiro[2-amino-4H-pyran-oxindole]s

Canadian Journal of Chemistry ◽

10.1139/cjc-2014-0345 ◽

2015 ◽

Vol 93 (5) ◽

pp. 546-549 ◽

Cited By ~ 10

Author(s):

Ali Reza Karimi ◽

Meysam Sourinia ◽

Zeinab Dalirnasab ◽

Marzie Karimi

Keyword(s):

Sulfuric Acid ◽

Magnetic Nanoparticle ◽

Ultrasound Irradiation ◽

Significant Loss ◽

Silica Sulfuric Acid ◽

One Pot ◽

External Magnet ◽

Three Component Reaction ◽

The One ◽

High Yields

Silica sulfuric acid magnetic nanoparticles efficiently catalyze the one-pot, three-component reaction of isatins and malononitrile with dimedone, 1,3-dimethylbarbituric acid or 4-hydroxycoumarin in EtOH–H2O to afford the corresponding spiro[2-amino-4H-pyran-oxindole] derivatives in high yields under ultrasound irradiation at 60 °C. The heterogeneous nanocatalyst could be recovered easily from the reaction mixture using an external magnet and reused many times without significant loss of its catalytic activity.

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Microwave-assisted efficient one-step synthesis of amides from ketones and benzoxazoles from (2-hydroxyaryl) ketones with acetohydroxamic acid using sulfuric acid as the catalyst

Tetrahedron Letters ◽

10.1016/j.tetlet.2011.09.019 ◽

2011 ◽

Vol 52 (46) ◽

pp. 6103-6107 ◽

Cited By ~ 19

Author(s):

Sridhar Madabhushi ◽

Narsaiah Chinthala ◽

Venkata Sairam Vangipuram ◽

Kondal Reddy Godala ◽

Raveendra Jillella ◽

...

Keyword(s):

Sulfuric Acid ◽

Acetohydroxamic Acid ◽

Microwave Assisted ◽

One Step

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N-Heterocyclic carbene-catalyzed enantioselective hetero-[10 + 2] annulation

Communications Chemistry ◽

10.1038/s42004-020-00425-7 ◽

2020 ◽

Vol 3 (1) ◽

Author(s):

Qiupeng Peng ◽

Shi-Jun Li ◽

Bei Zhang ◽

Donghui Guo ◽

Yu Lan ◽

...

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Density Functional Theory Calculations ◽

Higher Order ◽

Heterocyclic Carbenes ◽

Wide Scope ◽

Functional Theory ◽

One Step ◽

High Yields ◽

Powerful Strategy

AbstractHigher-order cycloadditions are a powerful strategy for the construction of polycycles in one step. However, an efficient and concise version for the induction of asymmetry is lacking. N-heterocyclic carbenes are widely used organocatalysts for asymmetric synthesis and could be an ideal choice for enantioselective higher-order cycloadditions. Here, we report an enantioselective [10 + 2] annulation between catalytically formed aza-benzofulvene intermediates and trifluoromethyl ketone derivatives. This protocol exhibits a wide scope, high yields, and good ee values, reflecting a robust and efficient higher-order cycloaddition. Density functional theory calculations provide an accurate prediction of the reaction enantioselectivity, and in-depth insight to the origins of stereocontrol.

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