Enantioselective Ni-Catalyzed 1,2-Borylalkynylation of Unactivated Alkenes.

Enantioselective three-component difunctionalization of alkenes with boron reagents represents an attractive strategy for assembling three-dimensional chiral organoboron compounds. However, regio- and enantiocontrol comprise the pivot challenges in these transformations, which predominantly require the use of activated conjugated alkenes. Herein, by utilizing various carbonyl directing groups, including amides, sulfinamides, ketones, and esters, we succeed in realizing a nickel-catalyzed 1,2-borylalkynylation of unactivated alkenes to enable the simultaneous incorporation of a boron entity and an sp-fragment across the double bond. The products contain boryl, alkynyl, and carbonyl functional groups with orthogonal synthetic reactivities, offering three handles for further derivatization to access valuable intermediates. The utility of this ligand-enabled asymmetric protocol has been highlighted through the late-stage decoration of drug-relevant molecules.

Trialkoxysilane-Induced Iridium-Catalyzed para-Selective C-H Bond Borylation of Arenes.

An ideal approach for the construction of aryl boron compounds is to selectively replace a C-H bond in arenes with a C-B bond, and controlling regioselectivity is one of the most challenging aspects of these transformations. Herein, we report an iridium-catalyzed trialkoxysilane protecting group-assisted regioselective C-H borylation of arenes, including derivatives of benzaldehydes, acetophenones, benzoic acids, benzyl alcohols, phenols, aryl silanes, benzyl silanes, and multi-functionalized aromatic rings are all well tolerated and gave the para -selective C-H borylation products in a short time without the requirement of inert gases atmosphere. The site-selective C-H borylation can be adjustable by installing the developed trialkoxysilane protecting group on different functional groups on one aromatic ring. Importantly, the preparation process of the trialkoxychlorosilane is efficient and scalable. Mechanistic and computational studies reveal that the steric hindrance of the trialkoxysilane protecting group plays a key role in dictating the para-selectivity.

Organic photoredox-catalyzed oxidative azolation of unactivated fluoroarenes.

Inexpensive and commercially available 2,4,6-triphenylpyrrolium tetrafluoroborate (TPT) is used as an organic photocatalyst for the nucleophilic aromatic substitution of unactivated fluoroarenes with pyrazole derivatives (SNAr) to form azole arenes. The use of organic photoredox catalysis enables the easy operation of this method under mild conditions. Various fluorinated aromatic compounds are suitable electrophiles for this transformation.

Ligand-Promoted Fluorinated Olefination of Isatins at the C5 Position via a Palladium Catalyst.

A palladium-catalyzed nondirected fluorinated olefination was developed. The oxalyl amide ligand greatly improved the yield of the reaction. A wide variety of isatin derivatives were well tolerated and yielded the corresponding products in moderate to good yields. Various fluorinated olefins were also compatible. The application and synthesis of bioactive compounds such as a Metisazone derivative highlight the synthetic value of this approach.

Exploring the Longitudinal Relationship Between Lockdown Policy Stringency and Public Negative Emotions Among 120 Countries During the COVID-19 Pandemic: Mediating Role of Population Mobility.

Background: To limit the spread of COVID-19, governments worldwide have implemented a series of lockdown policies to restrict the social activities of people. Although scholars suggest that such policies may produce negative effects on public emotions, the existing research is limited because it only provides a cross-sectional snapshot of the effect of lockdown policies in small and local samples. Using large-scale longitudinal cross-country data, the current study aims to gain a better understanding of the dynamic effect of lockdown policies on public emotions and their underlying mechanisms. Methods: Drawing on a large-scale longitudinal data from multiple sources, the study employs fixed-effects models to analyze the association between lagged lockdown policy stringency and public negative emotions among 120 countries from February to July 2020 (N = 9,141 country-day observations). The bootstrapping mediation test is used to examine the mediation effects of increased population mobility in residential areas. Results: The results show a statistically significant and positive association between lagged lockdown policy stringency and general public negative emotion (standardized coefficient = 0.32, CI = 0.30-0.35, p < 0.001). This pattern remains similar to other specific negative emotions, such as depression, anxiety, hopelessness, and helplessness. Moreover, the negative health effects of lockdown policy stringency are significantly mediated by increased mobility in residential areas (51-74% points, p < 0.001). Conclusion: The findings confirm that stringent lockdown policies have a negative effect on public emotions via confining population mobility residential areas. To tackle the COVID-19, future public health policies should pay more attention to the unintended negative consequences of lockdown measures on public emotions.

Ligand-Promoted Nickel-Catalyzed para-Selective Carboxylation of Anisoles.

It has always been a challenge in free radical chemistry to control site selectivity during the reaction of free radicals with aromatic rings. Herein, we report the site-selective carboxylation of anisoles through the direct reaction of the bromoform radical with a benzene ring at the para position under the assistance of 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline with nickel(II) as the catalyst. A wide variety of anisoles were compatible, leading to para-carboxylated products in moderate to good yields. A preliminary mechanistic study suggested that the Ni(II) complex coordinates with the methoxyl group of the aromatic ring, which may have increased the steric hindrance at the ortho and meta positions, while this weak interaction reduces the aromaticity of the aromatic ring, affording an activated phenyl ring, thereby leading to highly para-selective carboxylation.

The Association Between PM2.5 and Depression in China.

While China has been experiencing unprecedented economic growth, depression is becoming one of the most striking social and mental health problems in recent years. Such a paradox to progress may partially be due to the notoriously poor air quality of the country. To verify this argument, we constructed an index of the prevalence of depression (IPD) using internet search query volumes in Baidu to proxy the potential depression and examined how IPD is associated with PM2.5, the major air pollutant in China. Our results from 2-way fixed effects models reveal that a 100 µg·m-3 increase in previous week's PM2.5 in a city is significantly associated with 0.279 increase in its IPD, comparable to 7.34 hours decrease in weekly daylight, and such relationship is particularly pronounced in the spring and summer and in East and South areas. Our findings of large-scale pattern suggest that PM2.5 at current levels in China poses serious mental health risks.

The association between PM2.5 exposure and suicidal ideation: a prefectural panel study.

BACKGROUND: Suicidal ideation is subject to serious underestimation among existing public health studies. While numerous factors have been recognized in affecting suicidal thoughts and behaviors (STB), the associated environmental risks have been poorly understood. Foremost among the various environment risks were air pollution, in particular, the PM2.5. The present study attempted to examine the relationship between PM2.5 level and local weekly index of suicidal ideation (ISI). METHODS: Using Internet search query volumes in Baidu (2017), the largest internet search engine in China, we constructed a prefectural panel data (278 prefectures, 52 weeks) and employed dynamic panel GMM system estimation to analyze the relationship between weekly concentration of PM2.5 (Mean = 87 µg·m- 3) and the index of suicidal ideation (Mean = 49.9). RESULTS: The results indicate that in the spring and winter, a 10 µg·m- 3 increase in the prior week's PM2.5 in a Chinese city is significantly associated with 0.020 increase in ISI in spring and a 0.007 increase in ISI in winter, after taking account other co-pollutants and meteorological conditions. CONCLUSION: We innovatively proposed the measure of suicidal ideation and provided suggestive evidence of a positive association between suicidal ideation and PM2.5 level.

Mapping Public Concerns of Electronic Cigarettes in China.

E-cigarettes have gained growing visibility in recent years. However, there lacks a panoramic image of e-cigarette concerns, particularly in low-income countries, such as China. Studying the public concern at a macro level may help reveal the development of the e-cigarette market, and potential health burden of a province as a whole, which is crucial for the policy regulation of the e-cigarette market, and for the allocation of medical resources in the future. In this research, we attempt to provide the first representative portrait of e-cigarette concerns by using the index of e-cigarette search (ICS), which is constructed by online query of e-cigarette-related words/phrases of 31 provinces spanning from 2011 to 2014 in Baidu, the most popular search engine in China. E-cigarette concerns in all Chinese provinces increased over the time span. Our results from fixed-effects models further show that ICS is positively associated with the number of beds in medical institutions and road density of the province, but negatively associated with the proportion of urban population. In sum, provincial health care, infrastructure and urbanization are pivotal in shaping e-cigarette concerns at the provincial level in China.

A Direct Approach to Decoration of Bioactive Compounds via C-H Amination Reaction.

The development of new methods to achieve the direct synthesis of bioactive organic molecules is always an important topic in organic synthesis. We hereby demonstrate that N-methoxyamide is an excellent amino source in the iridium-catalyzed intermolecular C-H amination reaction. The linkage of two bioactive organic molecules can be well achieved with this new protocol. More than 20 examples of decorated bioactive compounds were reported, which can facilitate the discovery of new bioactive molecules.

Rh(III)-Catalyzed C-H Amidation of Arenes with N-Methoxyamide as an Amidating Reagent.

The Rh(III)-catalyzed amidation of C(sp2)-H bonds has been reported by employing the N-methoxyamide as a novel amino source. An excellent level of functional group tolerance can be achieved when N-methoxyamide derivatives are used as the amidating reagents. Importantly, several known bioactive compounds such as Aminalon, Pregabalin, Gabapentin, and Probenecid can be transformed to effective amidating reagents, as a way to facilitate the development of new bioactive molecules.

Using the Baidu Search Index to Predict the Incidence of HIV/AIDS in China.

Based on a panel of 30 provinces and a timeframe from January 2009 to December 2013, we estimate the association between monthly human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) incidence and the relevant Internet search query volumes in Baidu, the most widely used search engine among the Chinese. The pooled mean group (PMG) model show that the Baidu search index (BSI) positively predicts the increase in HIV/AIDS incidence, with a 1% increase in BSI associated with a 2.1% increase in HIV/AIDS incidence on average. This study proposes a promising method to estimate and forecast the incidence of HIV/AIDS, a type of infectious disease that is culturally sensitive and highly unevenly distributed in China; the method can be taken as a complement to a traditional HIV/AIDS surveillance system.

Discovery of Chromeno[4,3-c]pyrazol-4(2H)-one Containing Carbonyl or Oxime Derivatives as Potential, Selective Inhibitors PI3Kα.

A series of novel chromeno[4,3-c]pyrazol-4(2H)-one containing carbonyl or oxime derivatives (4a-n, 5a-n) have been synthesized and evaluated their biological activities as phosphatidyl inositol 3-kinase (PI3K) inhibitors. Out of them, compound 5l showed the most potent antiproliferative activities against HCT-116 with IC50 of 0.10 µM in vitro, and exhibited the most potent activity for PI3Kα with the value of 0.012 µM. Docking simulation of 5l into PI3Kα active site were performed to determine the probable binding model, and it indicated that compound 5l could be optimized as a potential inhibitor of PI3Kα in the further study.