Iodine(III)-Mediated C–H Alkoxylation of Aniline Derivatives with Alcohols under Metal-Free Conditions

The development of a novel intermolecular oxidative C–H alkoxylation of aniline derivatives is described under metal-free conditions with high reaction rates at ambient temperature. In the presence of an I­(III) oxidant, a range of aldehydes, anilines, and alcohol substrates undergo three-component coupling to produce synthetically useful alkoxyl-substituted <i>N</i>-arylimines. The preliminary mechanism investigations revealed that the transformation proceeds via imines as intermediates

Biomimetic Conversion of Glucose to Organic Acid Facilitated by Metalloporphyrin under Mild Conditions

Biomimetic catalytic conversion of carbohydrates to low-molecular weight (LWM) organic acids was investigated in the presence of sulfonated metalloporphyrins (MTSPP, M = Fe, Mn, Co, Cu), with dioxygen as the oxidant. The results showed that the selectivity of lactic acid reached 70%, starting from glucose with an iron complex of meso-tetra(4-sulfonato-phenyl)porphyrin (TSPPFeCl) as the catalyst at 433 K, and 0.6 MPa of O2 in 0.05 M NaOH aqueous solution. The effects of various metalloporphyrins on the selectivity of oxidative products were also considered. Experimental results show that TSPPFeCl exhibited the highest catalytic performance compared with TSPPMnCl, TSPPCo, and TSPPCu

Transition-Metal-Free Oxidative α‑C–H Amination of Ketones via a Radical Mechanism: Mild Synthesis of α‑Amino Ketones

A transition-metal-free direct α-C–H amination of ketones has been developed using commercially available ammonium iodide as the catalyst and sodium percarbonate as the co-oxidant. A wide range of ketone ((hetero)­aromatic or nonaromatic ketones) and amine (primary/secondary amines, anilines, or amides) substrates undergo cross-coupling to generate synthetically useful α-amino ketones. The mechanistic studies indicated that a radical pathway might be involved in the reaction process. The utility of the method is highlighted through a concise one-step synthesis of the pharmaceutical agent amfepramone

PIFA-Mediated Esterification Reaction of Alkynes with Alcohols via Oxidative Cleavage of Carbon Triple Bonds

A metal-free esterification of alkynes via CC triple bond cleavage has been developed. In the presence of phenyl­iodine bis­(tri­fluoro­acetate), a diverse range of alkyne and alcohol substrates undergoes triple bond cleavage to produce carboxylic ester motifs in moderate to good yields. The transformation is proposed to proceed via hydroxy­ethanones and ethane­diones as intermediates on the basis of mechanistic studies and exhibits a broad substrate scope and good functional group tolerance

Measurement and Correlation for Solubilities of Adipic Acid in Acetic Acid + ε‑Caprolactone Mixtures and Cyclohexanone + ε‑Caprolactone Mixtures

The solubilities of adipic acid in acetic acid + ε-caprolactone mixtures and in cyclohexanone + ε-caprolactone mixtures were measured by using the method of dynamic laser under atmospheric pressure. The experimental temperature ranged from 305.55 to 343.15 K, and the mass fraction of ε-caprolactone in the solvent mixtures ranged from 0.100 to 1.000, respectively. It was found that with the increasing of mass fraction of ε-caprolactone in solvent mixtures (0.100 to 1.000), the measured solubilities of adipic acid in acetic acid + ε-caprolactone mixtures decreased at the same temperature. However, in cyclohexanone + ε-caprolactone mixtures, the solubility showed an opposite trend with the increasing of mass fraction of ε-caprolactone in solvent mixtures. The experimental data were correlated by the modified NRTL activity coefficient model, and the values of the solubility calculated showed good agreement with the experimental observations

Depression Prevalence in Postgraduate Students and Its Association With Gait Abnormality

In recent years, an increasing number of university students are found to be at high risk of depression. Through a large scale depression screening, this paper finds that around 6.5% of the university postgraduate students in China experience depression. We then investigate whether the gait patterns of these individuals have already changed as depression is suggested to associate with gait abnormality. Significant differences are found in several spatiotemporal, kinematic and postural gait parameters such as walking speed, stride length, head movement, vertical head posture, arm swing, and body sway, between the depressed and non-depressed groups. Applying these features to classifiers with different machine learning algorithms, we examine whether natural gait analysis may serve as a convenient and objective tool to assist in depression recognition. The results show that when using a random forest classifier, the two groups can be classified automatically with a maximum accuracy of 91.58%. Furthermore, a reasonable accuracy can already be achieved by using parameters from the upper body alone, indicating that upper body postures and movements can effectively contribute to depression analysis