256 research outputs found

    Alcohol and tobacco consumption, personality, and cybervictimization among adolescents

    Get PDF
    Cyberbullying has emerged as a public health problem. Personality may play an important role in substance use and cybervictimization. The aim of this study was to examine whether tobacco and alcohol consumption and personality traits are associated with cybervictimization in Spanish adolescents. A cross-sectional study was conducted with 765 secondary students (aged 14–16) from 16 secondary schools in Spain. Participants completed a questionnaire assessing sociodemographic characteristics; tobacco and alcohol consumption; cybervictimization (Garaigordobil Scale); and personality traits (Big Five Questionnaire). A logistic regression model controlling for sex, age, parental education and personality traits was used to determine the independent associations and interactions between tobacco and alcohol consumption and cybervictimization. The results indicate that a total of 305 adolescents (39.9%) reported that they were cyberbullied in the past year. Girls were more likely to be cyberbullied than boys. Cybervictims had a significantly greater monthly alcohol consumption (OR = 1.51; 95% CI = 1.05–2.15), higher scores for extraversion (OR = 1.31; 95% CI = 1.06–1.63) and emotional instability (OR = 1.53; 95% CI = 1.27–1.83); as well as lower scores for conscientiousness (OR = 0.78; 95% CI = 0.63–0.95). These results suggest that personality traits and alcohol consumption are independently associated with cybervictimization. Our study suggests the existence of underlying common personality factors for cybervictimization and alcohol and tobacco use.Instituto de Salud Carlos III | Ref. PI12/0181

    Palladium-catalyzed intramolecular carbene insertion into C(sp3)-H bonds

    Get PDF
    A palladium‐catalyzed carbene insertion into C(sp3)−H bonds leading to pyrrolidines was developed. The coupling reaction can be catalyzed by both Pd0 and PdII, is regioselective, and shows a broad functional group tolerance. This reaction is the first example of palladium‐catalyzed C(sp3)−C(sp3) bond assembly starting from diazocarbonyl compounds. DFT calculations revealed that this direct C(sp3)−H bond functionalization reaction involves an unprecedented concerted metalation-deprotonation step

    Facile synthesis of azocino[4,3-b]indoles by ring-closing metathesis

    Get PDF
    The azocino[4,3-b]indole system, tricyclic substructure of the indole alkaloids apparicine and ervaticine, is efficiently assembled by ring-closing metathesis of 2-allyl-3-(allylaminomethyl)indoles. The metathesis sites are introduced into the indole nucleus by reductive amination of a 3-formyl derivative with allylamine, followed by a-lithiation with subsequent electrophilic trapping with acrolein

    Rapid Synthesis of the Ervitsine Alkaloid Skeleton by a Sequential RCM-Heck Cyclization Approach

    Get PDF
    An efficient approach to the bridged framework of the indole alkaloid ervitsine, featuring a ring-closing metathesis reaction from a 2,3-disubstituted indole followed by a vinyl halide Heck cyclization upon the resulting cycloheptene ring, is described

    Sequential ring-closing metathesis-vinyl halide Heck cyclization reactions: access to the tetracyclic ring system of ervitsine

    Get PDF
    A chemoselective indole-templated ring-closing metathesis is used to assemble the cyclohepta[b]indole substructure of the indole alkaloid ervitsine. A subsequent intramolecular Heck coupling of the resulting alkene functionality with an amino-tethered vinyl halide accomplishes the closure of the unique 2- azabicyclo[4.3.1]decane framework of the alkaloid with concomitant incorporation of the exocyclic Eethylidene substituent

    Exploration of Ring‐Closing Enyne Metathesis for the Synthesis of Azonino[5,4‐b]indoles

    Get PDF
    The use of the ring‐closing enyne metathesis (RCEYM) as a methodology for the synthesis of the azonino[5,4‐b]indole system, featuring the tricyclic substructure of the alkaloids cleavamine and quebrachamine, has been explored. Three series of enyne substrates were studied for their compatibility with the RCEYM reaction. In addition to the usual substrates bearing either a terminal or an internal alkyne, for the first time enynes with an alkynyl halide moiety were also considered. Although the metathesis cyclization allowed for assembly of the azoninoindole nucleus in all three series, an effective catalytic cycle was only noted for internal alkyne substrates. On the basis of the experimental results, the "yne‐then‐ene" pathway seems to be the mechanism at play in these reactions

    Palladium catalysis in intramolecular carbene C-H insertion of α-diazo-α-(methoxycarbonyl)acetamides to form β-lactams

    Get PDF
    The intramolecular carbene C-H insertion of α‐diazo‐α‐(methoxycarbonyl)acetamides leading to β‐lactams is effectively catalyzed by palladium complexes. It is found that although Pd0 catalysts typically produce mixtures of β‐lactams together with Buchner‐type reaction products, the use of PdII catalysts results in highly chemoselective transformations. According to DFT calculations, this insertion reaction occurs stepwise and involves an unprecedented PdII‐promoted Mannich‐type reaction through a metallacarbene‐induced zwitterionic intermediate

    Cybervictimization among secondary students: social networking time, personality traits and parental education

    Get PDF
    Background: Cyberbullying among children and adolescents is a major public health concern. However, research has not yet definitively identified the risk factors associated with cybervictimization. The purpose of this study was to determine the association of cybervictimization with use of social networks, personality traits and parental education in secondary students. Methods: The study population consisted of 765 secondary students (56.5% girls) from Majorca (Spain) who were aged 15.99 years (grade 4). The data were from the 16 secondary school centers that participated in the ITACA Project, a multi-center, cluster randomized controlled trial. Cybervictimization was measured by the Garaigordobil Cybervictimization Scale, and the Big Five Questionnaire for Children was used to assess personality traits. Results: Results showed that 39.9% of the students were cybervictims. Univariate analysis indicated that more girls than boys were cybervictimized (43.1% vs 35.7%). Cybervictims spent more time in social networking sites than non-victims (6 h 30 min vs. 5 h 16 min) and had greater emotional instability (0.16 vs. -0.23) and extraversion (0.11 vs. -0.09) and were less conscientious (− 0.001 vs. 0.20). Multivariable analysis indicated that social networking time was not significantly associated with cybervictimization after controlling for personality traits, but the same personality traits remained significantly associated. Conclusions: Our findings indicate that cyberbullying is a frequent and relevant problem in adolescents. Big Five personality traits are related with cybervictimization. Possible ways to design interventions include promoting social leisure activities, encourage responsible attitudes and provide stress coping toolsInstituto de Salud Carlos III | Ref. PI12/0181
    corecore