NiH-Catalyzed Regio- and Enantioselective Hydroalkylation for the Synthesis of ß- or γ-Branched Chiral Aromatic N-Heterocycles.

A nickel hydride-catalyzed regio- and enantioselective hydroalkylation reaction was developed to give access to a library of chiral ß- or γ-branched aromatic N-heterocycles. This intriguing asymmetric transformation features excellent selectivities, step- and atom-economies, and generating two kinds of chiral products through one synthetic strategy. Furthermore, the possible reaction mechanism was extensively investigated using numerous control experiments and density functional theory calculations.

Relationships Among Smartphone Use, Physical Activity, and Quality of Life in Chinese College Students.

This study aimed to investigate the correlations between smartphone use, physical activity, and quality of life (QOL) among Chinese college students. We enrolled 6323 students who were chosen from three Chinese universities. All participants completed the World Health Organization QOL Scale-Brief, Smartphone Addiction Index, and Physical Activity Questionnaire-Short Form. Smartphone addiction was negatively related to QOL (ß = -1.375), whereas physical activity was positively related to QOL (ß = .059). The presence of both smartphone addiction and insufficient physical activity decreased QOL scores when compared with the group with sufficient physical activity and non-smartphone addiction (ß = -36.505). Physical activity and smartphone use are potentially modifiable risk factors for poor QOL in college students. Thus, interventions to decrease smartphone use and promote physical activity could be beneficial for improving QOL in this population.

The effect of family structure on physical activity levels among children and adolescents in Western China in the era of COVID-19.

PURPOSE: This study aimed to examine the levels of physical activity (PA) among children and adolescents in western China, and the influence of parents on their PA, in the era of coronavirus disease 2019 (COVID-19). METHODS: This cross-sectional study used a multistage questionnaire to evaluate 4800 children and adolescents of grades 4-12 (9-17 years old) from 48 primary and secondary schools across 16 districts and counties in western China. In addition to PA, questionnaires collected data on demography, family structure, and exercise habits. Data were assessed using the International Physical Activity Questionnaire-Short Form (IPAQ-SF) and analyzed using chi-square tests, t-tests, Spearman's correlation, and logistic regression models in SPSS. RESULTS: In this study, a minority (42.1%, n = 1553) of children and adolescents met the daily exercise target (60 min) recommended by the World Health Organization (WHO). Moderate- to vigorous-intensity physical activity (MVPA) level of boys was significantly higher than that of girls. Regardless of sex, children with the highest MVPA levels were those in grades 4-6, and PA levels decreased with increasing age. Furthermore, for every hour of increase in the daily MVPA of parents, the MVPA also increased by 6.1-13.9 min in children and adolescents. Moreover, areas of higher economic development were associated with lower levels of MVPA. CONCLUSIONS: Overall, this study found a low level of MVPA in children and adolescents of western China; both family structure and parental activity have a significant influence on the children's PA levels. Besides, the impact of COVID-19 on PA levels has not been entirely negative.

Chiral 1,2,3-Triazolium Salt Catalyzed Asymmetric Mono- and Dialkylation of 2,5-Diketopiperazines with the Construction of Tetrasubstituted Carbon Centers.

Novel asymmetric mono- and dialkylation reactions of α-substituted 2,5-diketopiperazines catalyzed by new chiral spirocyclic-amide-derived triazolium organocatalysts have been developed, resulting in a range of enantioenriched 2,5-diketopiperazine derivatives containing one or two tetrasubstituted carbon stereocenters. The reactions feature high yields (up to 98%), and excellent cis-diastereo- and enantioselectivities (up to >20:1 dr, >99 % ee), and they provide a new asymmetric synthetic approach to important functionalized 2,5-diketopiperazine skeletons. Furthermore, a possible reaction mechanism was proposed based on both control experiments and extensive DFT calculations.