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1.
Molecules ; 28(4)2023 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-36838985

RESUMO

The design, synthesis, and initial study of amino-functionalized porphyrins as a new class of bifunctional catalysts for asymmetric organophotocatalysis is described. Two new types of amine-porphyrin hybrids derived from 5,10,15,20-tetraphenylporphyrin (TPPH2), in which a cyclic secondary amine moiety is covalently linked either to a ß-pyrrolic position (Type A) or to the p-position of one of the meso phenyl groups (Type B), were prepared by condensation, reductive amination, or amidation reactions from the suitable porphyrins (either formyl or methanamine derivatives) with readily available chiral amines. A preliminary study of the possible use of Type A amine-porphyrin hybrids as asymmetric, bifunctional organophotocatalysts was performed using the chiral, imidazolidinone-catalyzed Diels-Alder cycloaddition between cyclopentadiene 28 and trans-cinnamaldehyde 29 as a benchmark reaction. The yield and the stereochemical outcome of this process, obtained under purely organocatalytic conditions, under dual organophocatalysis, and under bifunctional organophotocatalysis, were compared.


Assuntos
Aminas , Porfirinas , Aminação , Catálise , Reação de Cicloadição , Estereoisomerismo
2.
Rev Panam Salud Publica ; 44: e57, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32973905

RESUMO

OBJECTIVE: To measure the impact generated by the implementation of the pharmacy-driven antimicrobial stewardship program of the Clínica Bíblica Hospital. METHODS: This is a retrospective observational study that evaluates the consumption of antibiotics for the periods before and during implementation of the Clínica Bíblica Hospital antimicrobial stewardship program, calculated by means of defined daily dose per 1 000 patient-days and days of therapy per 1 000 patient-days. In addition, bacterial resistance patterns for the periods 2014-2015 and 2016-2017 were compared. RESULTS: Consumption of most-used antibiotics was calculated, looking for trends that might be associated with the activities implemented by the Clínica Bíblica Hospital antimicrobial stewardship program. Comparing some of the antibiotics with the highest consumption in periods I and II, use of levofloxacin and ceftriaxone showed a decrease of 54.0% (p < 0.001) and 14.6% (p = 0.003), respectively, whereas there was an increase in the use of cefazolin of 4 539.3% (p < 0.001). Regarding percentage of bacterial resistance, in most bacterial isolates no statistically significant changes were observed between the two periods. CONCLUSIONS: A reduction in the overall consumption of antibiotics has been achieved over time, most likely attributable to the antimicrobial stewardship program. However, this trend was not observed for all the antibiotics studied. The pattern of resistance among the commonly isolated microorganisms did not vary greatly between the periods studied, which suggests that either the antimicrobial stewardship program may have prevented an increase in bacterial resistance since its implementation, or that it is too soon to see impact on bacterial resistance.

3.
ACS Catal ; 14(2): 751-756, 2024 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-38269040

RESUMO

We report a strong Brønsted acid-catalyzed three-component oxy-aminomethylation of styrenes with sym-trioxane and sulfonamides or carbamates. This transformation provides a variety of 1,3-oxazinanes in moderate to good yields under mild reaction conditions. The obtained heterocycles can be readily transformed into the corresponding 1,3-amino alcohols, which are useful building blocks for the synthesis of pharmaceutically relevant molecules. Mechanistic studies suggest the intermediacy of an in situ formed 1,3,5-dioxazinane and a subsequent reaction with the olefin.

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