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New strategies for asymmetric photocatalysis: asymmetric organocatalytic/photoredox relay catalysis for efficient synthesis of polycyclic compounds containing vicinal amino alcohols

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Science China Chemistry 2024年第3期67卷 945-952页

作者： Jia-Lu Zhang Wen-Bo He Xiu-Qin Hu Peng-Fei Xu State Key laboratory of applied Organic Chemistry College of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000China State Key laboratory of Veterinary Etiological biology College of Veterinary MedicineLanzhou UniversityLanzhou Veterinary Research InstituteChinese Academy of Agricultural SciencesLanzhou 730000China MOE Frontiers Science Center for Rare isotopes Lanzhou UniversityLanzhou 730000China

An asymmetric catalytic strategy in photocatalysis utilizing a chirality-induced approach through an organocatalytic/photoredox relay catalysis strategy is successfully achieved for the rapid construction of polycyclic compounds containing vicinal amino alcohols in a one-pot protocol. This methodology facilitates the efficient synthesis of diverse substituted polycyclic tetrahydroquinoline and benzofuran-derived vicinal amino alcohols, each containing five consecutive chiral centers, with high yields,excellent diastereoselectivities and enantioselectivities(up to 95% yield, >20:1 dr and 98% ee), under mild reaction conditions driven by sequential bifunctional squaramide organocatalyst-catalyzed [4+2] annulation and photocatalyst-catalyzed ketyl radical addition cyclization reaction process. Furthermore, investigations into the stereoselectivity mechanism and high-resolution mass spectrometry(HRMS) experiments on free radical trapping have provided evidence for elucidating the detailed mechanism of chirality-induced processes and chiral intermediate conversions in this procedure.

关键词： enantioselective photocatalysis asymmetric organocatalytic/photocatalysis relay catalysis five consecutive chiral centers chirality-induced strategy chirality vicinal amino alcohols

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Factors associated with H pylori epidemiology in symptomatic children in Buenos Aires,Argentina

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World Journal of Gastroenterology 2006年第33期12卷 5384-5388页

作者： Cinthia Goldman Andrés Barrado Mariana Janjetic Norma Balcarce Eduardo Cueto Rua Masaru Oshiro María L Calcagno Margarita Martinez Sarrasague Julián Fuda Ricardo Weill Marcela Zubillaga Guillermo I Perez-Perez José Boccio radioisotopes laboratory and laboratory of stable isotopes applied to biology and medicine Physics Department School of Pharmacy and Biochemistry University of Buenos Aires Buenos Aires Argentina laboratory of stable isotopes applied to biology and medicine Physics Department School of Pharmacy and Biochemistry University of Buenos Aires Buenos Aires Argentina Gastroenterology Unit Hospital de nios "Superiora Sor María Ludovica" La Plata Argentina Health Center Di Matteo San Fernando Buenos Aires Argentina Mathematics Department School of Pharmacy and Biochemistry University of Buenos Aires Buenos Aires Argentina Agrarian Industries Department School of Agronomy University of Morón Buenos Aires Argentina Departments of medicine and Microbiology New York University School of Medicine New York United States

AIM: To determine prevalence of H pylori infection in symptomatic children in Buenos Aires, Argentina, and to investigate factors associated with H pylori positivity. METHODS: A total of 395 children with upper gastrointestinal symptoms referred to the Gastroente-rology Unit of the Children Hospital “Sor Maria Ludovica” were evaluated for the presence of H pylori by the 13C-Urea Breath Test (13C-UBT). A questionnaire was applied to the recruited ***: Prevalence of H pylori infection was 40.0%in this population (mean age 9.97 ± 3.1 years). The factors associated with H pylori positivity were number of siblings (P < 0.001), presence of pet cats (P = 0.03) and birds (P = 0.04) in the household, and antecedents of gastritis among family members (P = 0.01). After multivariate analysis, number of siblings [Odds ratio (OR) = 1.39; 95% CI, 1.20-1.61] and contact with pet cats (OR = 1.76; 95% CI, 1.00-3.09) remained as variables associated with H pylori infection. CONCLUSION: The prevalence of H pylori infection in children with upper gastrointestinal symptoms in Argentina was similar to that reported in developed countries. Children from families with a higher crowding index and presence of pet cats have a higher risk of being colonized with H pylori.

关键词：流行病学幽门螺杆菌甲酮-钠除草剂阿根庭

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