Addition of silylated carbon nucleophiles to iminium and cyclic N-acyliminium ions promoted by InCl3

InCl3 was used as Lewis acid in the addition of silyl enolates and allyltrimethylsilane to aromatic aldimines and cyclic N-acyliminium ions derived from 5-acetoxylactams affording beta -aminocarbonyl systems and allyl adducts, respectively, in reasonable to good yields. The diastereofacial selectivity of cyclic N-acyliminium ions was investigated. (C) 2000 Elsevier Science Ltd. All rights reserved.41519939994

Probing the formation of monoalkyl carbonates and pyrocarbonates in water with electrospray ionization mass spectrometry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The anionic hemiesters of carbonic acid with aliphatic alcohols were demonstrated to be formed in aqueous medium containing HCO3- or CO32- by using electrospray ionization mass spectrometry (ESI-MS). Some monoalkyl carbonates (MACs) have been previously detected by capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-(CD)-D-4), but ESI-MS is structurally diagnostic and more sensitive allowing unequivocal characterization, which allowed, for the first time, detection of hydrogen pyrocarbonate and monoalkyl pyrocarbonates (MAPs). Methanol, ethanol, and different isomers of alcohols from C3 to C6 were studied. The relatively slow kinetics of formation of the MACs allowed us to confirm their formation in solution before the electrospray process takes place. The loss of CO2 to form the corresponding alkoxide is the most important process in gas phase dissociation, but dehydro-alkoxides were also observed. Monocyclohexyl and monocyclopentyl carbonates were also characterized by ESI-MS. These species, formed from cyclohexanol and cyclopentanol in diluted aqueous solution of HCO3-, are important because these alcohols are prototypes for the hydroxyl-containing portion of sterols. No biological role has been yet attributed to either MACs or MAPs, but their spontaneous formation in aqueous solution at room temperature indicates that these species are present in biological media.3411888618893Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)FAPESP [2012/06642-1, 2011/02156-2, 2012/15467-9]CNPq [304239/2010-0

On the mechanism of the Dakin-West reaction

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)The mechanism of the Dakin-West reaction has been thoroughly investigated by monitoring the reaction using ESI-MS/MS techniques in combination with M06-2X/6-311++ G(d,p) calculations. Several of the key intermediates in the previously proposed "azlactone" mechanism have been experimentally detected and characterized. In particular, interception of the mixed anhydrides involved in the early and late stages of the mechanistic scheme, as well as of the cyclic acyl-oxazolone intermediate, supports the original pathway suggested by Dakin and West. All intermediates and transition structures involved in several competing mechanisms have been calculated. The theoretical calculations support the experimental results and corroborate the proposed "azlactone" mechanism. The pathway involving the cyclic oxazolone ("azlactone") intermediate represents an energy barrier more than 3 kcal mol(-1) lower than for the competing aldol-type mechanism, thus ruling out this alternative mechanism. The DFT calculations explain the observed ESI-MS data and assess those intermediates which the experiments cannot fully elucidate.o TEXTO COMPLETO DESTE ARTIGO, ESTARÁ DISPONÍVEL À PARTIR DE AGOSTO DE 2015.104590139020Spanish Ministerio de Ciencia e InnovacionCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Synthesis of 5-Organotellanyl-1H-1,2,3-triazoles: Functionalization of the 5-Position Scaffold by the Sonogashira Cross-Coupling Reaction

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)An efficient synthesis of 5-organotellanyl-1H-1,2,3-triazole compounds was accomplished through [3+2] cycloaddition reaction of organic azides and (organotellanyl)alkynes. Additionally, 5-organotellanyl-1H-1,2,3-triazoles were readily functionalized at the 5-position by using a Sonogashira cross-coupling reaction, leading to highly functionalised triazoles. The regiochemistry of the products was assessed by two-dimensional NMR spectroscopic experiments and X-ray crystallography.1837803785Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)FAPESP [12/00424-2, 10/15677-8]CNPq [300.613/2007-5, 306532/2009-3]CAPES [808/2009

Perfil dos internos no sistema prisional do Rio de Janeiro: especificidades de gênero no processo de exclusão social Profile of prisoners in the Rio de Janeiro prison system: specifities of gender in the social exclusion process

O estudo do perfil sociodemográfico, história penal, uso de drogas e doenças sexualmente transmissíveis da população carcerária do Estado do Rio de Janeiro, em 1998, permitiu conhecer diferentes características da população prisional por sexo. O objetivo deste estudo é identificar se o perfil de exclusão social a que essa população é submetida difere quanto ao sexo. Foram entrevistados 2.039 presos por estudo seccional, e utilizada a razão de prevalência como medida de associação entre sexo e as demais variáveis. A análise multivariada, através de regressão logística, compõe um modelo final de explicação dessas diferenças. A população é jovem, de baixa escolaridade, e apresenta ruptura de vínculos da vida social em várias dimensões para ambos os sexos. Fatores mais fortemente associados ao sexo masculino: visita íntima na prisão, estar preso por sete anos ou mais, ser casado, condenação por roubo, ter ainda três anos ou mais a cumprir de pena e uso de maconha antes de ser preso; para o sexo feminino: doença sexualmente transmissível, ser viúva, estrangeira, usar tranqüilizante na prisão, ter visitado alguém na prisão antes de ser presa e ter 35 anos ou mais. A análise dos dados permitiu concluir que embora esses homens e mulheres sejam igualmente excluídos da "vida social" muito antes e também depois da prisão, existem algumas características que os diferenciam nesse processo de injustiça social.<br>The study of the social and demographic profile, criminal records, drug use and sexually transmitted diseases of the prison population of Rio de Janeiro State in 1998 offered a view of different aspects of this population by gender. The objective of this study is to identify if the profile of social exclusion this population is submitted differs by gender. Through a sectional study, 2,039 prisoners were interviewed, using the prevalence ratio as an association measure between gender and the other variables. Multivariate analysis, using logistical regression, explains these differences in a final model. This population is young and poorly educated, with breakdowns in the links of social life at various levels for both men and women. Factors most strongly associated with men: marital visits in jail, imprisoned for seven years or more, married, sentenced for robbery, have three years or more of the sentence to complete, and having smoked marijuana prior to being arrested; for women: sexually transmitted disease, widowed, non-Brazilian, take tranquilizers in jail, visited someone in jail before being arrested, 35 years old or more. Data analysis permits to conclude that although these men and women are just as excluded from "social life" long before and also after their imprisonment, there are some aspects that make them different in this process of social injustice