RESUMO

N-Alkyl-N-(2-(1-arylvinyl)aryl)cinnamamides are converted into natural product inspired scaffolds via iridium photocatalyzed intramolecular [2+2] photocycloaddition. The protocol has a broad substrate scope, whilst operating under mild reaction conditions. Tethering four components forming a trisubstituted cyclobutane core builds rapidly high molecular complexity. Our approach allows the design and synthesis of a variety of tetrahydrocyclobuta[c]quinolin-3(1H)-ones, in yields ranging between 20-99 %, and with excellent regio- and diastereoselectivity. Moreover, it was demonstrated that the intramolecular [2+2]-cycloaddition of 1,7-enynes-after fragmentation of the cyclobutane ring-leads to enyne-metathesis-like products.

RESUMO

A transition metal- and oxidant-free visible light-photoinduced protocol for direct functionalization of 2-methylquinolines has been developed. This protocol enabled the C-H functionalization of substituted 2-methylquinolines with diacetyl or ethyl pyruvate, under environmentally friendly conditions. A mechanistic investigation based on density functional theory (DFT) calculations provided details about the origins of reactivity and selectivity.

RESUMO

A radical cascade process initiated through visible-light induced thiyl radical coupling with ortho-substituted arylisocianides followed by an intramolecular cyclization and subsequent aromatization to access 2-sulfenylindoles is described. The key thiyl radicals are promptly generated via a hydrogen atom transfer event. The redox-neutral protocol features broad substrate scope, excellent functional group tolerance, and mild reaction conditions. Furthermore, the implementation of a continuous flow variant allows smooth scalability with a short residence time through process intensification.

RESUMO

OBJECTIVE: To evaluate the applicability and the psychometric properties of Montreal Cognitive Assessment Brazilian Version (MoCA-BR) in the elderly, as well as comparing its accuracy as a tracking test for mild cognitive impairment (MCI) and mild Alzheimer's disease (AD) with the accuracy of Mini-Mental State Examination (MMSE). METHOD: A transversal study was performed in 4 reference medical centers that care for the elderly. In all, 229 elderly participated in the study. To select the sample, the clinical history of the elderly, Pfeffer Functional Activities Questionnaire, and neuropsychological battery, apart from MMSE and MoCA-BR cognitive tests, were selected. The elderly were classified into control, MCI, and mild AD groups. RESULTS: There was a significant statistical difference between the MoCA-BR scores of the elderly and the control group, MCI, and mild AD (p < 0.001). The Cronbach alpha for MoCA-BR was 0.77, indicating a good internal consistency. The test-retest reliability was elevated, with intraclass correlation coefficient (ICC) 0.91. The inter-examiner reliability was excellent (ICC 0.96). The area under curve of the receiver operating characteristics curve was 0.95, when evaluating the ability of MoCA-BR to discriminate between the elderly with cognitive impairment and cognitively healthy elderly. CONCLUSIONS: The results of the study show that the Brazilian version of MoCA is a reliable cognitive tracking tool and is accurate for the detection of MCI and early stage AD, with good applicability on the elderly with education equal to or more than 4 years and adequate to discriminate between cognitively healthy elderly, and those with MCI and mild, proving to be superior to MMSE in tracking MCI and similar to this test when tracking mild AD.

Assuntos

Doença de Alzheimer/diagnóstico , Doença de Alzheimer/psicologia , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/psicologia , Testes de Estado Mental e Demência/normas , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Brasil , Diagnóstico Precoce , Feminino , Humanos , Masculino , Programas de Rastreamento , Psicometria , Reprodutibilidade dos Testes , Traduções

RESUMO

OBJECTIVE: To propose cutoff scores for the Brazilian version of the Montreal Cognitive Assessment (MoCA-BR) stratified by education in order to detect mild cognitive impairment (MCI) and mild Alzheimer's disease (AD) in the elderly. METHOD: A transversal study in health centers was performed on 159 elderly people with 4-12 years of education and 70 of their peers with over 12 years of schooling. The MoCA-BR cutoff scores for screening cognitive impairment were determined based on an ROC curve analysis. RESULTS: The ROC curve analysis indicated that cutoff scores under 20 were good for screening elderly people with cognitive impairment with more than 12 years of education, and scores under 21 were good for screening those with 4-12 years of education. CONCLUSIONS: MoCA-BR scores under 21 points (after adding 1 point to the elderly with ≤12 years of education) indicate a need to continue the diagnostic investigation with regular follow-ups.

RESUMO

In the title compound, C21H21NO5, obtained from a Morita-Baylis-Hillman adduct, the hydrogenated five-membered ring adopts a shallow envelope conformation, with the C atom bearing the carb-oxy-lic acid substituent deviating by 0.237 (1) Šfrom the mean plane of the other four atoms (r.m.s. deviation = 0.007 Å). The dihedral angle between the fused ring system (all atoms; r.m.s. deviation = 0.057 Å) and the pendant trimeth-oxy benzene ring is 66.65 (3)°. The C atoms of the meta-meth-oxy groups lie close to the plane of the benzene ring [deviations = 0.052 (1) and -0.083 (1) Å], whereas the C atom of the para-meth-oxy group is significantly displaced [deviation = -1.289 (1) Å]. In the crystal, carb-oxy-lic acid inversion dimers generate R 2 (2)(8) loops. The dimers are connected by N-H⋯O hydrogen bonds, forming [011] chains. A C-H⋯O inter-action is also observed.