Tag: 300-400

Fuentes, Jose A.; Janka, Mesfin E.; Rodgers, Jody; Fontenot, Kevin J.; Buhl, Michael; Slawin, Alexandra M. Z.; Clarke, Matthew L. published their research in Organometallics on December 13 ,2021. The article was titled 《Effect of Ligand Backbone on the Selectivity and Stability of Rhodium Hydroformylation Catalysts Derived from Phospholane-Phosphites》.Recommanded Product: (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol The article contains the following contents:

A study on how ligand backbone structure has an impact on selectivity, rate, and catalyst stability of hydroformylation catalysts was prompted by some longer-term stability issues being discovered for a phospholane-phosphite with a [-CH2O-] backbone. Phospholane-phosphite ligands were synthesized. Catalysts made in situ from these ligands and [Rh(acac)(CO)2] gave iso-butanal selectivities up to 75% at 75-105°: the latter being a benchmark for iso-selectivity in reactions conducted at industrially meaningful temperatures A racemic Rh complex of a bidentate phospholane-phosphite from a tropos-biphenol with an extended backbone showed unusually high stability at high temperatures, combined with even better iso-selectivity in propene hydroformylation relative to the original complex. A related ligand with an electron-withdrawing group maintained the unusually high stability and improved activity. Characterization of the precatalysts [RhH(CO)2(L)] was accomplished using in situ HPIR spectroscopy and backed up by d. functional theory calculations (B3PW91-D3 level) and by NMR studies; the latter showed that the variation of the backbone also had a pronounced impact on the precatalyst structure. A key finding is that it is now possible to prepare phospholane-phosphite ligands that deliver high iso-butanal selectivity and that show no signs of degradation after several days even above typical reaction temperatures In one stability test, several kilograms of aldehydes were produced with TOF and selectivity being consistent over several days. In the experiment, the researchers used (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol(cas: 329735-68-4Recommanded Product: (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol)

(R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol(cas: 329735-68-4) belongs to phenols. Phenols are more acidic than typical alcohols. The acidity of the hydroxyl group in phenols is commonly intermediate between that of aliphatic alcohols and carboxylic acids (their pKa is usually between 10 and 12).Recommanded Product: (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol

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Name: (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diolOn September 25, 2006 ,《Zirconium Bis(Amido) Catalysts for Asymmetric Intramolecular Alkene Hydroamination》 was published in Organometallics. The article was written by Watson, Donald A.; Chiu, Melanie; Bergman, Robert G.. The article contains the following contents:

In situ combination of diphosphinic amides and Zr(NMe2)4 gave chiral Zr bis(amido) complexes. The complexes are competent catalysts for intramol. asym. alkene hydroamination, providing piperidines and pyrrolidines in up to 80% ee and high yield. This system uses an inexpensive precatalyst, readily prepared ligands and is the 1st asym. alkene hydroamination catalyst based upon a neutral Zr bis(amido) complex. In the experiment, the researchers used (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol(cas: 329735-68-4Name: (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol)

(R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol(cas: 329735-68-4) belongs to phenols. Phenols are more acidic than typical alcohols.Name: (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol The acidity of the hydroxyl group in phenols is commonly intermediate between that of aliphatic alcohols and carboxylic acids (their pKa is usually between 10 and 12).

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In 2011,Chemistry – An Asian Journal included an article by Shi, Ce; Chien, Chih-Wei; Ojima, Iwao. Reference of (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol. The article was titled 《Synthesis of Chiral Biphenol-Based Diphosphonite Ligands and their Application in Palladium-Catalyzed Intermolecular Asymmetric Allylic Amination Reactions》. The information in the text is summarized as follows:

A library of new 2,2′-bis(diphenylphosphinoyloxy)-1,1′-binaphthyl (binapo)-type chiral diphosphonite ligands was designed and synthesized based on chiral 3,3′,5,5′,6,6′-hexasubstituted biphenols. These bop ligands have exhibited excellent efficiency in a palladium-catalyzed intermol. allylic amination reaction, which provides a key intermediate for the total synthesis of Strychnos indole alkaloids with enantiopurities of up to 96 % ee. In addition to this study using (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol, there are many other studies that have used (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol(cas: 329735-68-4Reference of (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol) was used in this study.

(R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol(cas: 329735-68-4) belongs to phenols. Phenols are more acidic than typical alcohols. The acidity of the hydroxyl group in phenols is commonly intermediate between that of aliphatic alcohols and carboxylic acids (their pKa is usually between 10 and 12).Reference of (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol

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Name: (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diolOn October 23, 2017 ,《Molybdenum-Catalyzed Enantioselective Synthesis of Planar-Chiral (η5-Phosphacyclopentadienyl)manganese(I) Complexes and Application in Asymmetric Catalysis》 was published in Organometallics. The article was written by Ogasawara, Masamichi; Tseng, Ya-Yi; Uryu, Mizuho; Ohya, Naoki; Chang, Ninghui; Ishimoto, Hiroto; Arae, Sachie; Takahashi, Tamotsu; Kamikawa, Ken. The article contains the following contents:

Enantioselective desymmetrization of Cs-sym. (η5-2,5-dialkenylphospholyl)(allyldiphenylphosphine)manganese(I) dicarbonyl complexes 1 was realized by Mo-catalyzed asym. ring-closing metathesis (ARCM), and the corresponding bridged planar-chiral phosphacymantrene derivatives 2 were obtained in good yields with excellent enantioselectivity. The enantioselectivity of the ARCM reaction was strongly influenced by the structures of the phospholyl-bound alkenyl groups, and the highest enantioselectivity of up to 99% ee was achieved in the reaction of 1d,e, which possess the 2-methylpropenyl substituents at the 2- and 5-positions of the η5-phospholides. Single-enantiomeric planar-chiral 2d, which was obtained by the recrystallization of the highly enantiomerically enriched ARCM product, can serve as a chiral ligand for the Pd-catalyzed asym. allylic alkylation to show good enantioselectivity in up to 74% ee. The experimental part of the paper was very detailed, including the reaction process of (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol(cas: 329735-68-4Name: (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol)

(R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol(cas: 329735-68-4) belongs to phenols. Phenols are more acidic than typical alcohols.Name: (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol The acidity of the hydroxyl group in phenols is commonly intermediate between that of aliphatic alcohols and carboxylic acids (their pKa is usually between 10 and 12).

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

SDS of cas: 329735-68-4On November 15, 2001 ,《Phosphonites Based on the Paracyclophane Backbone: New Ligands for Highly Selective Rhodium-Catalyzed Asymmetric Hydrogenation》 appeared in Organic Letters. The author of the article were Zanotti-Gerosa, Antonio; Malan, Christophe; Herzberg, Daniela. The article conveys some information:

The synthesis of new phosphonites with a chiral paracyclophane backbone is described. The Rh complexes derived from the phosphonites (e.g. I) bearing biphenoxy and binaphthoxy substituents are highly active and highly selective catalysts for the asym. hydrogenation of dehydroamino acids and esters. For example, >99% N-acetylalanine Me ester with 99 %ee was obtained in 1/2 h using the Rh complex of I.(R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol(cas: 329735-68-4SDS of cas: 329735-68-4) was used in this study.

(R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol(cas: 329735-68-4) belongs to phenols. Phenols are more acidic than typical alcohols.SDS of cas: 329735-68-4 The acidity of the hydroxyl group in phenols is commonly intermediate between that of aliphatic alcohols and carboxylic acids (their pKa is usually between 10 and 12).

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

《(S)-2-[(N-arylamino)methyl]pyrrolidines-Based Phosphoramidite P,N-Ligand Library for Asymmetric Metal-Catalyzed Allylic Substitution and Conjugate 1,4-Addition》 was published in ChemistrySelect in 2016. These research results belong to Gavrilov, Konstantin N.; Mikhel, Igor S.; Chuchelkin, Ilya V.; Zheglov, Sergey V.; Gavrilov, Vladislav K.; Birin, Kirill P.; Tafeenko, Victor A.; Chernyshev, Vladimir V.; Goulioukina, Nataliya S.; Beletskaya, Irina P.. SDS of cas: 329735-68-4 The article mentions the following:

A library of easy-to-prepare and modular chiral P,N-phosphoramidites based on [1,1′-biaryl]-2,2′-diols and C1-sym. 1,2-diamines was designed and developed. The structures of the novel ligands were elucidated by 2-dimensional-NMR and confirmed in the solid state by x-ray diffraction anal. Stereoselectors of this type exhibited high enantioselectivities in Pd-catalyzed allylic substitution reactions of (E)-1,3-diphenylallyl acetate with NaSO2-p-Tol (up to 91% ee), CH2(CO2Me)2 (up to 89% ee), Pr2NH (up to 94% ee) and (EtO)2P(O)CH2NH2 as a novel nucleophile (up to 98% ee). Ee values of up to 88% and 72% were obtained in the Pd-catalyzed desymmetrization of N,N’-ditosyl-meso-cyclopent-4-ene-1,3-diol biscarbamate and in the Cu-catalyzed 1,4-conjugate addition of diethylzinc to chalcone, resp. The reactions of P,N-bidentate ligands with [Pd(Cod)Cl2] at molar ratios of L/M = 1 and 2 were studied using 1H, 13C, 13C-1H HSQC, 13C-1H HMBC, 1H-1H COSY, 1H-1H ROESY, DOSY and 31P NMR spectroscopy as well as HR ESI mass spectrometry. The results came from multiple reactions, including the reaction of (R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol(cas: 329735-68-4SDS of cas: 329735-68-4)

(R)-3,3′-Di-tert-butyl-5,5′,6,6′-tetramethylbiphenyl-2,2′-diol(cas: 329735-68-4) belongs to phenols. Phenols are more acidic than typical alcohols.SDS of cas: 329735-68-4 The acidity of the hydroxyl group in phenols is commonly intermediate between that of aliphatic alcohols and carboxylic acids (their pKa is usually between 10 and 12).

Referemce:
Alcohol – Wikipedia,
Alcohols – Chemistry LibreTexts

Srivastava, Abhishek; Sharma, Vivek; Singh, Vinay Kumar; Srivastava, Krishna published an article in 2022, the title of the article was A simple and sensitive inhibitory kinetic method for the carbocisteine determination.COA of Formula: C12H24O11 And the article contains the following content:

A fast, reproducible, and sensitive method is proposed for the kinetic determination of carbocisteine (CCys). The method depends on the inhibitory property of carbocisteine, which reduces the Hg2+ catalyzed substitution rate of cyanide from [Ru(CN)6]4- with N-R-salt (1-Nitroso-2-naphthol-3,6-disulfonic acid disodium salt) via forming a stable complex with Hg2+. Spectrophotometric measurements were carried out by recording the absorbance at 525 nm (λmax of [Ru(CN)5 Nitroso-R-Salt]3- complex) at a fixed time of 10 and 15 min under the optimized reaction conditions with [N-R-salt] = 4.5 x 10-4 M, I = 0.05 M (KNO3), Temp = 45.0 ± 0.2°C, pH = 7.0 ± 0.03, [Hg2+] = 8.0 x 10-5 M and [Ru(CN)64-] = 4.25 x 10-5 M. With the proposed method, CCys can be determined quant. down to 3.0 x 10-6 M. This methodol. can be effectively used for the rapid quant. estimation of CCys in the pharmaceutical samples with good accuracy and reproducibility. The addition of common excipients in pharmaceuticals even up to 1000 times with [CCys] does not interfere significantly in the estimation of CCys. The experimental process involved the reaction of SweetPearlR P300 DC Maltitol(cas: 585-88-6).COA of Formula: C12H24O11

The Article related to carbocisteine inhibitory kinetic method, Pharmaceutical Analysis: General and other aspects.COA of Formula: C12H24O11

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On December 31, 2020, DeJong, Amy E.; Hartel, Richard W. published an article.Synthetic Route of 585-88-6 The title of the article was Quantification of γ-sorbitol crystal growth rate and solubility in the presence of mannitol and maltitol. And the article contained the following:

In many confectionery systems, an understanding of crystallization behavior is essential for proper control of product texture. While this knowledge is well developed in sucrose-based systems, there is little information on controlling crystallization in sugar-free systems, such as those formulated with sorbitol. By leveraging such advances in time domain-NMR (TD-NMR) methodol., the impact of mannitol and maltitol on modulating sorbitol crystal growth in sugar-free systems. Binary and ternary systems of sorbitol mixed with mannitol, maltitol, or a mixture thereof were evaluated at total impurity addition levels of 10% and 20%. Polyol mixtures were dissolved in water, evaporated to 10% moisture, and mixed with γ sorbitol seed crystals to create a sugar-free fondant. Fondants were crystallized at 25°C, and crystal content was measured using TD-NMR over time. Crystal content increased rapidly at the start but quickly tapered off to a final asymptote indicating phase equilibrium In all systems, the addition of impurities decreased the extent and rate of sorbitol crystallization, with mannitol having the greatest impact on rate. When both mannitol and maltitol were present as impurities, the rate of crystallization was reduced to a greater extent. At the highest level of mannitol, the final crystal content increased, presumably because mannitol also crystallized Controlling sorbitol crystallization in the presence of impurities is a key to controlling quality in certain confections. The experimental process involved the reaction of SweetPearlR P300 DC Maltitol(cas: 585-88-6).Synthetic Route of 585-88-6

The Article related to mannitol maltitol gamma sorbitol crystal growth solubility, td-nmr, crystallization, impurities, kinetics, polyol, sorbitol, Food and Feed Chemistry: Analysis and other aspects.Synthetic Route of 585-88-6

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On October 1, 2022, Scettri, Anna; Schievano, Elisabetta published an article.Reference of SweetPearlR P300 DC Maltitol The title of the article was Quantification of polyols in sugar-free foodstuffs by qNMR. And the article contained the following:

We present a qNMR method for the determination of low calories sweeteners (erythritol, mannitol, maltitol, sorbitol, isomalt and xylitol) in sugar-free foodstuff. The structural similarities of these compounds determine often a severe spectral overlap that hampers their quantification via conventional 1D and 2D NMR spectra. This problem is here overcome by exploiting the resolving capabilities of the CSSF-TOCSY experiment, allowing the quantification of all six polyols, with satisfactory results in terms of LoQ (2.8-7.4 mg/L for xylitol, mannitol, sorbitol, 15 mg/L for erythritol, 38 mg/L for maltitol and 91 mg/L for isomalt), precision (RSD% 0.40-4.03), trueness (bias% 0.15-4.81), and recovery (98-104%). Polyols quantification in different sugar-free confectionary products was performed after a simple water extraction without any addnl. sample treatment. While these results demonstrate the robustness of the proposed method for polyols quantification in low calories foods, its applicability can be further extended to other food matrixes or biofluids. The experimental process involved the reaction of SweetPearlR P300 DC Maltitol(cas: 585-88-6).Reference of SweetPearlR P300 DC Maltitol

The Article related to polyol quantification sugar free foodstuff nmr, polyols, sugar alcohols, sugar-free foodstuff, qnmr, Food and Feed Chemistry: Analysis and other aspects.Reference of SweetPearlR P300 DC Maltitol

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On March 31, 2022, Setyaningsih, Widiastuti; Putro, Andika Wicaksono; Fathimah, Rohmah Nur; Kurnia, Kiki Adi; Darmawan, Noviyan; Yulianto, Brian; Jiwanti, Prastika Krisma; Carrera, Ceferino A.; Palma, Miguel published an article.HPLC of Formula: 585-88-6 The title of the article was A microwave-based extraction method for the determination of sugar and polyols: Application to the characterization of regular and peaberry coffees. And the article contained the following:

The brewing properties of coffee products are defined by the chem. composition in the bean, including sugars and polyols. Some factors, such as coffee species and roasting, may affect the level of these compounds in the bean. A new anal. microwave-assisted extraction (MAE) method has been developed to extract sugars and polyols from the coffee bean. The studied extraction conditions for the MAE were temperature (30-80°C), solvent composition (0-50% ethanol in water), and solvent-to-sample ratio (10:1-30:1 mL solvent per g sample). A Box-Behnken design was applied to study the effect of extraction variables, and subsequently, the influential variables were optimized by response surface methodol. (RSM). In addition to the main effect of the solvent-to-sample ratio, all quadratic effects significantly influenced (p < 0.05) the recovery of sugars and polyols from the coffee beans. RSM suggested the optimized MAE conditions: temperature 52°C, ethanol concentration in water 18.5%, and solvent-to-sample ratio 17:1. Under the optimum condition, a kinetics study confirmed that 15 min showed high precision and accuracy of the developed method. Ultimately, a real sample application of the developed MAE revealed that the new method successfully described the composition of sugars and polyols in regular and peaberry coffee beans. Addnl., the method also effectively characterized the green and roasted Arabica and Robusta coffee beans. The experimental process involved the reaction of SweetPearlR P300 DC Maltitol(cas: 585-88-6).HPLC of Formula: 585-88-6

The Article related to peaberry coffee maltose saccharose glycerol microwave extraction, Food and Feed Chemistry: Analysis and other aspects.HPLC of Formula: 585-88-6

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