First, in situ generated Mannitol-Boron or Sorbitol-Boron chelate complex as a novel, recyclable catalyst for the highly efficient synthesis of bis(indolyl)methanes, tris(indolyl)methanes and diindolyl (carbazolyl)methanes.

Lavanya, G.; Magesh, Chinnan J.; Venkatapathy, K.

doi:10.1016/j.cdc.2020.100342

Cited by 2 publications

(3 citation statements)

References 30 publications

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“…It is known that the accuracy of an analytical method is typically assessed by using standard reference material. Since the standard reference material of tourmaline was not available in this current work, the accuracy of the proposed HF-HNO 3 –mannitol-based digestion method M Tour -2 was then evaluated by a B recovery study of anhydrous Li 2 B 4 O 7 , which provides borate species [ 44 ] to form boron–mannitol chelate complexes [ 45 ]. With 10 mg of this reagent treated by method M LT -1 in which the quantity of 2% mannitol was increased to 2.5 mL according to sample B content [ 46 ], the B concentration was determined with the results collected in Table 2 .…”

Section: Resultsmentioning

confidence: 99%

Accurate Boron Determination in Tourmaline by Inductively Coupled Plasma Mass Spectrometry: An Insight into the Boron–Mannitol Complex-Based Wet Acid Digestion Method

Tan,

Feng,

Zhou

et al. 2024

Molecules

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Tourmaline, a boron-bearing mineral, has been extensively applied as a geothermometer, provenance indicator, and fluid-composition recorder in geological studies. In this paper, the decomposition capability of an HF-HNO3–mannitol mixture for a tourmaline sample was investigated in detail for the first time, and a wet acid digestion method based on the boron–mannitol complex for accurate boron determination in tourmaline by inductively coupled plasma mass spectrometry (ICP-MS) was proposed. With a digestion temperature of 140 °C, tourmaline samples of 25 mg (±0.5 mg) can be completely decomposed by a ternary mixture, which consisted of 0.6 mL of HF, 0.6 mL of HNO3, and 0.7 mL of 2% mannitol (wt.), via a continuous heating treatment of 36 h. Following gentle evaporation at 100 °C, the sample residues were re-dissolved using 2 mL of 40% HNO3 solution (wt.) and diluted to about 2.0 × 105-fold by a two-step method using 2% HNO3 solution (wt.). The boron contents in a batch of parallel tourmaline samples were then determined by ICP-MS, and results showed that the boron concentration levels were in a range of 3.20–3.44% with determination RSDs less than 4.0% (n = 5). It was found that the boron concentrations obtained at the mass of 10B were comparable with results from the measurements at the mass of 11B. This revealed that the usage of 2% mannitol with a quantity as high as 0.7 mL in this developed approach did not exhibit significant effect on the quantification accuracy of boron at the mass of 11B. It was also found that the processes including fluoride-forming prevention and fluoride decomposition deteriorated the boron-reserving efficiency of mannitol for tourmaline, causing the averaged boron contents to vary from 2.25% to 3.57% (n = 5). Furthermore, the stability of the boron–mannitol complex under 185 °C by applying the laboratory high pressure-closed digestion method was evaluated, which showed that there existed a 60.36% loss of boron compared to that under 140 °C by using this proposed approach. For this ternary mixture, the tourmaline decomposing efficiency was found to be weakened prominently using 100 °C as the digestion temperature, and tourmaline powders can be observed even after 72 h of continuous heating with B contents within 1.09–1.23% (n = 5). To assess the accuracy of this developed method, the boron recovery of anhydrous lithium tetraborate was studied. It was found that the boron recoveries were within 96.59–102.12% (RSD < 1%, n = 5), demonstrating the accuracy and reliability of this proposed method, which exhibits advantages of high B preserving efficiency, and giving concentration information of both B and trace elements simultaneously. By applying such a boron–mannitol complex-based wet acid digestion method, the chemical composition of boron and trace elements in three tourmaline samples from different pegmatites were quantified, which provided valuable information to distinguish regional deposits and the associated evolution stages.

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Section: Resultsmentioning

confidence: 99%

Accurate Boron Determination in Tourmaline by Inductively Coupled Plasma Mass Spectrometry: An Insight into the Boron–Mannitol Complex-Based Wet Acid Digestion Method

Tan,

Feng,

Zhou

et al. 2024

Molecules

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“…A few protocols are reported in literature using various catalyst and solvent such as enzymes, [21] meglumine, [22] thiamine hydrochloride, [23] graphene oxide, [24] ethyl lactate, [25] sulphated polyborate, [26] Lewis acids, [27–32] Brønsted acids, [33] heteropoly acids, [34–36] solid acids, [37–42] ionic liquids, [43] metal complexes, [44–46] 4‐sulfophthalic acid [47] and Iodine/tert‐Butyl Hydroperoxide [48] . Recently, a number of methodologies have been developed in this field [49–68] . A generalize scheme for the different processes so far reported in literature are drawn in Scheme 1.…”

Section: Introductionmentioning

confidence: 99%

“…[48] Recently, a number of methodologies have been developed in this field. [49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66][67][68] A generalize scheme for the different processes so far reported in literature are drawn in Scheme 1. But some of these protocols have many drawbacks like use of toxic metal salts or catalytic systems with expensive reagents, photosensitive catalysts, high catalyst loadings, high temperatures, chromatographic purifications, costly catalyst as well as solvent, time consuming during preparation of catalyst, harsh reaction conditions and hazardous solvent.…”

Section: Introductionmentioning

confidence: 99%

Humic acid: A Biodegradable Organocatalyst for Solvent‐free Synthesis of Bis(indolyl)methanes, Bis(pyrazolyl)methanes, Bis‐coumarins and Bis‐lawsones

Mitra

Ghosh

2021

ChemistrySelect

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Humic acid, a biodegradable, non‐toxic and easily accessible high molecular weight organocatalyst has been explored for the straightforward and environmentally benign approach towards the preparation of diverse array of functionalized bis(indolyl)methanes, bis(pyrazolyl)methanes, bis‐coumarins and bis‐lawsones by the reaction of a vast range of aldehydes with indole, 3‐methyl‐1‐phenyl pyrazolone, 4‐hydroxycoumarin and 2‐hydroxynaphthalene‐1,4‐dione respectively under solvent‐free condition. These protocols proceed without any hazardous solvents, toxic metal catalysts and harsh reaction conditions. In addition, low catalyst loading, good yield and excellent functional group tolerance are the key advantages of these protocols. The used catalyst and solvent‐free approach make this strategy safe to our mother earth. For the first time reusability of humic acid was investigated and found that it can be recycled up to fifth run without any significant loss of its activity at the end of the reaction. Some bioactive molecules such as arundine, trisindoline and vibribdole A were easily synthesized in our lab by utilizing this designed strategy.

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First, in situ generated Mannitol-Boron or Sorbitol-Boron chelate complex as a novel, recyclable catalyst for the highly efficient synthesis of bis(indolyl)methanes, tris(indolyl)methanes and diindolyl (carbazolyl)methanes.

Cited by 2 publications

References 30 publications

Accurate Boron Determination in Tourmaline by Inductively Coupled Plasma Mass Spectrometry: An Insight into the Boron–Mannitol Complex-Based Wet Acid Digestion Method

Accurate Boron Determination in Tourmaline by Inductively Coupled Plasma Mass Spectrometry: An Insight into the Boron–Mannitol Complex-Based Wet Acid Digestion Method

Humic acid: A Biodegradable Organocatalyst for Solvent‐free Synthesis of Bis(indolyl)methanes, Bis(pyrazolyl)methanes, Bis‐coumarins and Bis‐lawsones

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