Palladium-Catalyzed Site-Selective Fluorination of Unactivated C(sp3)−H Bonds

The transition-metal-catalyzed direct C–H bond fluorination is an attractive synthetic tool toward the preparation of organofluorines. While many methods exist for the direct sp3 C–H functionalization, site-selective fluorination of unactivated sp3 carbons remains a challenge. Direct, highly site-selective and diastereoselective fluorination of aliphatic amides via a palladium-catalyzed bidentate ligand-directed C–H bond functionalization process on unactivated sp3 carbons is reported. With this approach, a wide variety of β-fluorinated amino acid derivatives and aliphatic amides, important motifs in medicinal and agricultural chemistry, were prepared with palladium acetate as the catalyst and Selectfluor as the fluorine source

Fairness in online vehicle-cargo matching: An intuitionistic fuzzy set theory and tripartite evolutionary game approach

This paper explores the concept of fairness and equitable matching in an on-line vehicle-cargo matching setting, addressing the varying degrees of satisfaction experienced by shippers and carriers. Relevant indicators for shippers and carriers in the on-line matching process are categorized as attributes, expectations, and reliability, which are subsequent quantified to form satisfaction indicators. Employing the intuitionistic fuzzy set theory, we devise a transformed vehicle-cargo matching optimization model by combining the fuzzy set's membership, non-membership, and uncertainty information. Through an adaptive interactive algorithm, the matching scheme with fairness concerns is solved using CPLEX. The effectiveness of the proposed matching mechanism in securing high levels of satisfaction is established by comparison with three benchmark methods. To further investigate the impact of considering fairness in vehicle-cargo matching, a shipper-carrier-platform tripartite evolutionary game framework is developed under the waiting response time cost (WRTC) sharing mechanism. Simulation results show that with fairness concerns in vehicle-cargo matching, all stakeholders are better off: The platform achieves positive revenue growth, and shippers and carriers receive positive subsidy. This study offers both theoretical insights and practical guidance for the long-term and stable operation of the on-line freight stowage industry.Comment: 36 pages, 15 figure

Transient ligand‐enabled transition metal‐catalysed C‐H functionalisation

Transition metal‐catalysed C‐H bond functionalisation is one of the most efficient and powerful strategies in synthetic organic chemistry to derivatize otherwise inert sites of organic molecules for the construction of C‐C and C‐heteroatom bonds. However, additional steps are often required in order to install the directing groups to realize the positional functionalisation of the substrates. These tedious steps run counter to the step‐economical nature of the C‐H activation. In contrast, direct functionalisation of the substrate, utilizing the transient ligands, avoids the unnecessary steps for the prefunctionalisation of the substrates. In this mini review, we will provide a short journey for the major progress made in this field for the C‐H functionalisation on sp2 and sp3 carbon centres with different transient working modes, including the covalent, hydrogen, and ionic bonds

Benzisothiazol‐3‐ones through a Metal‐Free Intramolecular N–S Bond Formation

The highly efficient synthesis of benzoisothiazol‐3‐ones from thiobenzamides has been described with good functional group compatibility and excellent yields. This work represents the first example of selectfluor‐promoted N–S bond formation processes. This method provides a facile approach to access various important bioactive benzoisothiazol‐3‐ones

Cobalt-catalysed site-selective intra- and intermolecular dehydrogenative amination of unactivated sp3 carbons

Cobalt-catalysed sp2 C–H bond functionalization has attracted considerable attention in recent years because of the low cost of cobalt complexes and interesting modes of action in the process. In comparison, much less efforts have been devoted to the sp3 carbons. Here we report the cobalt-catalysed site-selective dehydrogenative cyclization of aliphatic amides via a C–H bond functionalization process on unactivated sp3 carbons with the assistance of a bidentate directing group. This method provides a straightforward synthesis of monocyclic and spiro β- or γ-lactams with good to excellent stereoselectivity and functional group tolerance. In addition, a new procedure has been developed to selectively remove the directing group, which enables the synthesis of free β- or γ-lactam compounds. Furthermore, the first cobalt-catalysed intermolecular dehydrogenative amination of unactivated sp3 carbons is also realized., Functionalizing unactivated carbon–hydrogen bonds is challenging, especially when using non-precious metals and dealing with sp3 hybridized carbons. Here, the authors report an intramolecular cobalt catalysed amination of C–H bonds of sp3 carbons, giving access to β- and γ-lactams

Palladium-catalyzed ligand-promoted site-selective cyanomethylation of unactivated C(sp3)–H bonds with acetonitrile

The direct cyanomethylation of unactivated sp3 C–H bonds of aliphatic amides was achieved via palladium catalysis assisted by a bidentate directing group with good functional group compatibility. This process represents the first example of the direct cross-coupling of sp3 C–H bonds with acetonitrile. Considering the importance of the cyano group in medicinal and synthetic organic chemistry, this reaction will find broad application in chemical research

Penghou, a new genus of flea beetles from China (Coleoptera: Chrysomelidae: Galerucinae: Alticini)

A new genus (Penghou) with a single new species (P. yulongshan) from Yunnan Province in China is described and illus- trated. It is compared to Hespera Weise, Hesperomorpha Ogloblin, Laotzeus Chen, Luperomorpha Weise, Mandarella Duvivier, Omeiana Chen, Stenoluperus Ogloblin and Taiwanohespera Kimoto

Penghou, a new genus of flea beetles from China (Coleoptera: Chrysomelidae: Galerucinae: Alticini)

A new genus (Penghou) with a single new species (P. yulongshan) from Yunnan Province in China is described and illus- trated. It is compared to Hespera Weise, Hesperomorpha Ogloblin, Laotzeus Chen, Luperomorpha Weise, Mandarella Duvivier, Omeiana Chen, Stenoluperus Ogloblin and Taiwanohespera Kimoto

The relationship between childhood trauma and Internet gaming disorder among college students: A structural equation model

open access journalBackground The aim of this study was to investigate the mechanisms of Internet gaming disorder (IGD) and the associated interaction effects of childhood trauma, depression and anxiety in college students. Methods Participants were enrolled full-time as freshmen at a University in the Hunan province, China. All participants reported their socio-demographic characteristics and undertook a standardized assessment on childhood trauma, anxiety, depression and IGD. The effect of childhood trauma on university students' internet gaming behaviour mediated by anxiety and depression was analysed using structural equation modelling (SEM) using R 3.6.1. Results In total, 922 freshmen participated in the study, with an approximately even male-to-female ratio. A mediation model with anxiety and depression as the mediators between childhood trauma and internet gaming behaviour allowing anxiety and depression to be correlated was tested using SEM. The SEM analysis revealed that a standardised total effect of childhood trauma on Internet gaming was 0.18, (Z = 5.60, 95% CI [0.02, 0.05], P < 0.001), with the direct effects of childhood trauma on Internet gaming being 0.11 (Z = 3.41, 95% CI [0.01, 0.03], P = 0.001), and the indirect effects being 0.02 (Z = 2.32, 95% CI [0.00, 0.01], P = 0.020) in the pathway of childhood trauma-depression-internet gaming; and 0.05 (Z = 3.67, 95% CI [0.00, 0.02], P < 0.001) in the pathway of childhood trauma-anxiety-Internet gaming. In addition, the two mediators anxiety and depression were significantly correlated (r = 0.50, Z = 13.54, 95% CI [3.50, 5.05], P < 0.001). Conclusions The study revealed that childhood trauma had a significant impact on adolescents' Internet gaming behaviours among college students. Anxiety and depression both significantly mediated the relationship between childhood trauma and internet gaming and augmented its negative influence. Discussion of the need to understand the subtypes of childhood traumatic experience in relationship to addictive behaviours is included