Co-Catalyzed Hydrofluorination of Alkenes: Photocatalytic Method Development and Electroanalytical Mechanistic Investigation.

The hydrofluorination of alkenes represents an attractive strategy for the synthesis of aliphatic fluorides. This approach provides a direct means to form C(sp3)-F bonds selectively from readily available alkenes. Nonetheless, conducting hydrofluorination using nucleophilic fluorine sources poses significant challenges due to the low acidity and high toxicity associated with HF and the poor nucleophilicity of fluoride. In this study, we present a new Co(salen)-catalyzed hydrofluorination of simple alkenes utilizing Et3N·3HF as the sole source of both hydrogen and fluorine. This process operates via a photoredox-mediated polar-radical-polar crossover mechanism. We also demonstrated the versatility of this method by effectively converting a diverse array of simple and activated alkenes with varying degrees of substitution into hydrofluorinated products. Furthermore, we successfully applied this methodology to 18F-hydrofluorination reactions, enabling the introduction of 18F into potential radiopharmaceuticals. Our mechanistic investigations, conducted using rotating disk electrode voltammetry and DFT calculations, unveiled the involvement of both carbocation and CoIV-alkyl species as viable intermediates during the fluorination step, and the contribution of each pathway depends on the structure of the starting alkene.

Deuterodehalogenation Under Net Reductive or Redox-Neutral Conditions Enabled by Paired Electrolysis.

Interest in deuterated active pharmaceutical ingredients (APIs) is increasing as deuteration holds promise for kinetic isotope effect (KIE) regulated fine-tuning of API performance. Moreover, deuterium isotope labeling is frequently carried out to study organic and bioorganic reaction mechanisms and to facilitate complex target synthesis. As such, methods for highly selective deuteration of organic molecules are highly desirable. Herein, we present an electrochemical method for the selective deuterodehalogenation of benzylic halides via a radical-polar crossover mechanism, using inexpensive deuterium oxide (D2 O) as the deuterium source. We demonstrate broad functional group compatibility across a range of aryl and heteroaryl benzylic halides. Furthermore, we uncover a sequential paired electrolysis regime, which permits switching between net reductive and overall redox-neutral reactions of sulfur-containing substrates simply by changing the identity of the sacrificial reductant employed.

Online Social Networking and Mental Health among Older Adults: A Scoping Review.

As the number of older adults is expected to increase exponentially within the next few decades, loneliness, social isolation, and depression among seniors are growing public health concerns. Although formal treatment options, such as therapy and medication, can be helpful for depression, they can also be expensive and sometimes ineffective. It is therefore important to consider other potential treatment options and social interventions. Alternative methods for addressing mental health issues are especially important for older adults, as they may encounter barriers associated with aging such as limited mobility and decreased social networks. In these circumstances, online social networking may offer a potential "social cure" to alleviate loneliness, social isolation, and depression. The purpose of this scoping review was to gather and summarize the current literature on associations between online social networking and mental health outcomes (e.g., depression, life satisfaction, loneliness) among older adults. An initial search of 3,699 articles resulted in 52 articles that met criteria for inclusion. Five common themes were identified: (1) enhanced communication with family and friends, (2) greater independence and self-efficacy, (3) creation of online communities, (4) positive associations with well-being and life satisfaction, and (5) decreased depressive symptoms. Implications for older adults' mental health, social connectedness, programs and policies are discussed.

Titanium and Cobalt Bimetallic Radical Redox Relay for the Isomerization of N-Bz Aziridines to Allylic Amides.

Herein a bimetallic radical redox-relay strategy is employed to generate alkyl radicals under mild conditions with titanium(III) catalysis and terminated via hydrogen atom transfer with cobalt(II) catalysis to enact base-free isomerizations of N-Bz aziridines to N-Bz allylic amides. This reaction provides an alternative strategy for the synthesis of allylic amides from alkenes via a three-step sequence to accomplish a formal transpositional allylic amination.

New Redox Strategies in Organic Synthesis by Means of Electrochemistry and Photochemistry.

As the breadth of radical chemistry grows, new means to promote and regulate single-electron redox activities play increasingly important roles in driving modern synthetic innovation. In this regard, photochemistry and electrochemistry-both considered as niche fields for decades-have seen an explosive renewal of interest in recent years and gradually have become a cornerstone of organic chemistry. In this Outlook article, we examine the current state-of-the-art in the areas of electrochemistry and photochemistry, as well as the nascent area of electrophotochemistry. These techniques employ external stimuli to activate organic molecules and imbue privileged control of reaction progress and selectivity that is challenging to traditional chemical methods. Thus, they provide alternative entries to known and new reactive intermediates and enable distinct synthetic strategies that were previously unimaginable. Of the many hallmarks, electro- and photochemistry are often classified as "green" technologies, promoting organic reactions under mild conditions without the necessity for potent and wasteful oxidants and reductants. This Outlook reviews the most recent growth of these fields with special emphasis on conceptual advances that have given rise to enhanced accessibility to the tools of the modern chemical trade.

Sex differences in the impact of secondhand harm from alcohol on student mental health and university sense of belonging.

PURPOSE: University students report high rates of secondhand harm from alcohol (i.e., harm from another person's drinking). The current study investigated the association between students' exposure to secondhand harm and student mental health and university sense of belonging. We also assessed whether students' sense of belonging mediated the association between secondhand harm and mental health and sex differences in these associations. METHODS: A total of 941 students (70% female) completed an online survey. Path analysis was employed to test our hypotheses. Secondhand harm was assessed across three dimensions; strains (e.g., having sleep/studies interrupted), threats (e.g., physical/sexual assault), and interpersonal harm (e.g., taking care of intoxicated friends). RESULTS: Eighty-nine percent of participants reported secondhand harm exposure in the last 30 days. Interpersonal harm was the most common type of harm experienced by students. Strains were associated with higher levels of anxiety and stress, threats were associated with higher levels of anxiety and depression, and interpersonal harm predicted higher levels of anxiety, depression, and stress. Gender moderated these effects, such that only interpersonal harm was associated with men's mental health outcomes. Sense of belonging was associated with fewer mental health symptoms, and significantly mediated the effect of threats on anxiety, depression, and stress for females only, such that threat exposure was associated with reduced sense of belonging, which in turn increased anxiety, depression, and stress. CONCLUSION: This study supports the growing body of literature demonstrating the high prevalence of secondhand harm exposure among university students and the association of these experiences with poor student mental health. Furthermore, this research provides evidence that sense of belonging may be one mechanism that explains this association.