Oxidative Nucleophilic Cyclization of 2‑Alkynylanilines with Thiophenols under Metal-Free Conditions

An oxidative nucleophilic cyclization of 2-alkynylanilines with thiophenols under metal-free conditions was developed. The one-pot two-step reaction involves a PhI­(OAc)₂-mediated oxidative dearomatization and a Brønsted acid promoted nucleophilic cyclization. DFT calculations were performed to understand the reaction pathway

Dearomatization-Induced Cycloaddition and Aromatization-Triggered Rearrangement: Synthesis of Vertically Expanded Five-Ring Fused Benzofurans

A dearomatization strategy has been developed for the efficient construction of vertically expanded five-ring fused benzofurans from <i>ortho</i>-alkynylphenols and <i>ortho</i>-alkynylarylaldimines. The stepwise procedure comprises a dearomatization-induced silver-catalyzed [3 + 2] cycloaddition followed by an aromatization-triggered ytterbium-catalyzed rearrangement

Efficient Synthesis of Arylated Carbazole from Cyclopentadienyliron Complexes

Arylated carbazoles are valuable intermediates in the preparation of organic functional materials. The present work addresses an improved process for the preparation of arylated carbazoles. This process involves a nucleophilic substitution between the cyclopentadienyliron complexes of chloroarenes and carbazole or hydroxyl carbazole, followed by photolysis of cyclopentadienyliron complexes of arylated carbazoles (Fc-carbazole). The described process combines two steps in good yields and is cost-effective, and thus, it is a practical route of preparation of arylated carbazoles. The purification strategy of arylated carbazoles was subjected to crystallization instead of column chromatography, which is very good for their industrial applications. The arylated carbazoles products were determined by Fourier transform infrared (FT-IR), liquid chromatography mass spectroscopy (LC-MS), and NMR

Theoretical Investigation on Mechanistic and Kinetic Transformation of 2,2′,4,4′,5-Pentabromodiphenyl Ether

This study investigates the decomposition of 2,2′,4,4′,5-pentabrominated diphenyl ether (BDE99), a commonly detected pollutant in the environment. Debromination channels yielding tetrabrominated diphenyl ethers and hydrogen abstracting aromatic bromine atom formations play significant roles in the reaction of BDE99 + H, in which the former absolutely predominates bimolecular reactions. Polybrominated dibenzo-<i>p</i>-dioxins (PBDDs) and polybrominated dibenzofurans (PBDFs) can be produced during BDE99 pyrolysis, especially for PBDFs under inert conditions. The expected dominant pathways in a closed system are debromination products and PBDF formations. The bimolecular reaction with hydroxyl radical mainly leads to hydroxylated BDE99s rather than hydroxylated tetrabrominated diphenyl ethers. PBDDs are then generated from <i>ortho</i>-hydroxylated PBDEs. HO₂ radical reactions rarely proceed. The total rate constants for the BDE99 reaction with hydrogen atoms and hydroxyl radicals exhibit positive dependence on temperature with values of 1.86 × 10^–14 and 5.24 × 10^–14 cm³ molecule^–1 s^–1 at 298.15 K, respectively

Computational Study on the Mechanisms and Rate Constants of the Cl-Initiated Oxidation of Methyl Vinyl Ether in the Atmosphere

The Cl-initiated oxidation reactions of methyl vinyl ether (MVE) are analyzed by using the high-level composite method CBS-QB3. Detailed chemistry for the reactions of MVE with chlorine atoms is proposed according to the calculated thermodynamic data. The primary eight channels, including two Cl-addition reactions and six H-abstraction reactions, are discussed. In accordance with the further investigation of the two dominant additional routes, formyl chloride and formaldehyde are the major products. Over the temperature range of 200–400 K and the pressure range of 100–2000 Torr, the rate constants of primary reactions are calculated by employing the MESMER program. H-abstraction channels are negligible according to the value of rate constants. During the studied temperature range, the Arrhenius equation is obtained as <i>k</i>_tot = 5.64 × 10^–11 exp­(215.1/<i>T</i>). The total rate coefficient is <i>k</i>_tot = 1.25 × 10^–10 cm³ molecule^–1 s^–1 at 298 K and 760 Torr. Finally, the atmospheric lifetime of MVE with respect to Cl is estimated to be 2.23 h

MOESM1 of Multivariate random regression analysis for body weight and main morphological traits in genetically improved farmed tilapia (Oreochromis niloticus)

Additional file 1: Table S1. Phenotypic (Lower triangle) and family (Upper triangle) correlations of body lengths between pairwise the selected days of age. Table S2 Phenotypic (Lower triangle) and family (Upper triangle) correlations of body depths between pairwise the selected days of age. Table S3 Phenotypic correlations between body weights and body lengths at the selected days of age. Table S4 Phenotypic correlations between body weights and body depths at the selected days of age. Table S5 Phenotypic correlations between body lengths and body depths at the selected days of age

Determination and Correlation of Solubility of Quetiapine Fumarate in Nine Pure Solvents and Two Aqueous Binary Solvents

A gravimetric method was used to determine the solubility of quetiapine fumarate (QF) in nine pure solvents and two aqueous binary solvents (water + methanol/ethanol) at different temperatures from 283.15 to 323.15 K. The solubility of QF increases with the increase of temperature in nine pure solvents, and it is in the order DMF > methanol > ethanol >1-butanol > isopropyl alcohol > (acetone > ethyl acetate > isobutyl alcohol) > water at low temperature, and in the order DMF > methanol > ethanol >1-butanol > isopropyl alcohol > (acetone > isobutyl alcohol > ethyl acetate) > water at relatively high temperature at a given temperature. The solubility of QF in the binary solvents also shows temperature dependence, while at a given temperature the solubility is mainly influenced by the solvent composition with the presence of maximum, reflecting cosolvency. Also the solubility of QF increases with the increase of temperature in binary solvents in a given composition. The Hansen solubility parameters were used to explain the cosolvency and maxima shift, confirming that for large values (>25 MPa^1/2) of solute, the solubility shows a peak in the range of 35 to 31 MPa^1/2 of solubility parameters of alcohol mixtures. The experimental solubility of QF in pure and binary solvents is well correlated by modified Apelblat equation, the nonrandom two-liquid model, and the CNIBS/R-K equation, respectively

Tubular Monolayer Superlattices of Hollow Mn₃O₄ Nanocrystals and Their Oxygen Reduction Activity

Self-assembled nanocrystal (NC) superlattices are emerging as an important class of materials with rationally modulated properties. Engineering the nanoscale structure of constituent building blocks as well as the mesoscale morphology of NC superlattices is a crucial step in widening their range of applications. Here, we report a template-assisted epitaxial assembly strategy, enabling growth of freestanding, carbon-coated tubular monolayer superlattices (TMSLs). Specifically, we design and construct TMSLs of hollow Mn₃O₄ NCs (h-Mn₃O₄-TMSLs) by exploiting structural evolution of MnO NCs. The tubular superlattices obtained possess a number of unique and advantageous structural features unavailable in conventional NC superlattices, rendering them particularly attractive for energy conversion applications. We demonstrate this by employing h-Mn₃O₄-TMSLs as electrocatalysts for oxygen reduction, the catalytic performance of which is comparable to that of state-of-the-art Pt/C catalysts and superior to that of most manganese oxide-based catalysts reported

Polymorph Control by Investigating the Effects of Solvent and Supersaturation on Clopidogrel Hydrogen Sulfate in Reactive Crystallization

Reactive crystallization and polymorphic transformation of clopidogrel hydrogen sulfate (CHS) in nine pure solvents were studied at 313.15 K. It is found that thermodynamically stable polymorphic form tends to be obtained in solvents with higher solubility of CHS and the conversion rates from form I to form II are also mainly increased with increasing solubility. The solvent hydrogen bond donor ability is essential for determining the solvent effects on solubility and polymorphic formation of CHS. Besides, the reactive crystallization of CHS at different supersaturations in 2-propanol and 2-butanol was monitored online by using ATR-FTIR and FBRM with a calibration-based approach. The results indicate the nucleation induction period is the kinetic-determining stage and supersaturation is a direct factor to determine the polymorphic formation of CHS: form II was obtained with <i>s</i> under 18 while form I was produced when <i>s</i> increases above 21

Solubility Measurement and Correlation of Fosfomycin Sodium in Six Organic Solvents and Different Binary Solvents at Temperatures between 283.15 and 323.15 K

The solubility data of fosfomycin sodium (FOM-Na) in six pure solvents (methanol, ethanol, propanol, cyclohexane, acetone, <i>N</i>,<i>N</i>-dimethylformamide) and two binary solvents (methanol + ethanol, methanol + acetone) at temperatures ranging from 283.15 to 323.15 K were measured by a laser monitoring dynamic method at atmospheric pressure. It turned out that the solubility data decreased with increasing temperature, and also varies with the composition of the solvents. Moreover, the experimental data in pure solvents have been correlated with two thermodynamic models (i.e., modified Apelblat and van’t Hoff), and the data in binary solvents have been correlated with CNIBS/R-K equation and two modified versions of Jouyban–Acree models (Van’t-JA equation and Apel-JA equation), respectively. All the results showed a good agreement with the experimental data. Intermolecular interaction force and dielectric constants are introduced to explain the relationship between solubility and temperature. In addition, the analysis of the solubilities implies that higher temperature may destroy the forces between the solvent and solute molecules, leading to lower solubility. And this can give a guide to the design and optimization of the crystallization process of FOM-Na in the industry