Preparação do (+)-±-terpineol a partir do (+)-limoneno: monoterpenos de odor agradável em um projeto para química orgânica experimental

A synthesis of (+)-±-terpineol from (+)-limonene was proposed as a project for undergraduate organic laboratory course. Terpineol is a useful flavor and fragrance compound, and several aspects of this preparation are suited for experimental organic classes, including basic techniques for extraction and analyses of essential oils, different reaction types and the possibility of a high degree of student interest.

O Instituto de Química da Universidade Federal do Rio de Janeiro, da pós-graduação à incorporação dos cursos de graduação: uma perspectiva histórica

This work intends to present the history of top-level Chemistry education in Rio de Janeiro. It's important to rescue the history of Chemistry Institute of Federal University of Rio de Janeiro since 1959. It's also important to understand the incorporation of two undergraduate courses: Chemistry and Chemistry bachelor's degree. It covers historical background of Chemistry education in old National Faculty of Philosophy, considering power disputes between Industrial Chemistry Course and Chemical Engineering; when and in which circumstances the Institute was created; political context and its relation with postgraduate. Finally, discuss the incorporation of undergraduate courses and curriculum modifications since 1968.

Aplicação de α-oxoceteno ditiocetais em síntese orgânica

The synthesis and reactivity of α-oxoketenes dithioacetals (S,S-acetals), general structure [(R¹C=OC(R²)=C(SR³)(SR4)], are reported. We also showed the application of S,S acetals as synthons for efficient synthesis of isoxazoles, pyrazoles, indazoles, thiophenes, dithiol thiones, pyridines, pyrimidines and other heterocycles. This work aims to review the importance of α-oxoketenes dithioacetals in organic chemistry during the past few years.

El aprendizaje basado en problemas como estrategia para el cambio metodológico en los trabajos de laboratorio

The Problem Based Learning (PBL) can be used as a strategy for methodological change in conventional learning environments. In this paper, the integration of laboratory work in PBL grounded activities during an introductory organic chemistry course is described. The most decisive issues of their implementation are discussed. The results show how this methodology favours the laboratory work contextualization in subject-matter and promotes the Science-Technology-Society-Environment relationships. Besides, it contributes to competence development like planning and organization skills, information search and selection, cooperative work, etc., the same way as the tutorial action improvement.

A Química Quântica na compreensão de teorias de Química Orgânica

Quantum chemical calculations were performed in order to obtain molecular properties such as electronic density, dipole moment, atomic charges, and bond lengths, which were compared to qualitative results based on the theories of the organic chemistry. The quantum chemistry computational can be a useful tool to support the main theories of the organic chemistry.

Recentes aplicações sintéticas de compostos orgânicos tricloro(bromo)metila substituídos

This review presents the recent applications of some trihalomethyl carbinols, α,α,α-trihalogenated carbonyl compounds and trichloro(bromo)methyl-containing heterocycles, acting as high versatile synthetic precursors in organic chemistry, based on the last 10 years' literature.

Adição de anilinas à naftoquinona em água e em fase sólida

Considering all the aspects of the principles of green chemistry, we present herein the addition reactions of amines to 1,4-naphthoquinone in water as solvent and also in solid phase. These reactions resulted in very colorful products that were easily monitored by thin layer chromatography and consequently easy to separate. Therefore, they are interesting experiments for experimental organic chemistry in the classrooms or in the laboratories.

Montagem de uma prensa para fios de sódio metálico

Several organic chemistry labs in Brazil suffers from the absence of a safe method to extrude sodium wire, used to obtain anhydrous solvents such as THF or ethyl ether. This technical note presents the assembly instructions for a sodium wire press, similar to the one that has been used for the past four years in our laboratory without any maintenance.

A importância da lei de Gay-Lussac para a classificação dos compostos orgânicos

This article shows the genesis of the law of volumes of combining gases, formulated by Gay-Lussac in 1808, and how it allowed the expression of the composition of organic compounds in terms of whole numbers of volumes, thus leading to the first classification of organic compounds, formulated by Dumas and Boullay in 1828. It was from this work that Organic Chemistry began to shed its purely taxonomic nature, analogous to what prevailed in Natural History, and to then develop in a vigorous and continuous process, initiating what may be the most significant historical phenomenon in the History of Chemistry of the nineteenth century.

Miniprojeto para ensino de Química Orgânica Experimental baseado no acoplamento catalítico N-C promovido por micro-ondas

This paper describes a three-week mini-project for an Experimental Organic Chemistry course. The activities include N-C cross-coupling synthesis of N-(4-methoxyphenyl) benzamide in an adapted microwave oven by a copper catalyst (CuI). Abilities and concepts normally present in practical organic chemistry courses are covered: use of balances, volumetric glassware, separation of mixtures (liquid-liquid extraction and filtration), chromatographic techniques, melting point determination and stoichiometric calculations.

Inovação & propriedade industrial & indústria química

ABSTRACT The main aim of this paper was to contribute to reflections in Brazil on the need to transfer knowledge held at universities and R&D institutions over to companies, i.e. to transfer scientific knowledge of chemistry to technology. It discusses how the competitiveness of countries is increasingly dependent on their technological capacity. The chemicals industry is a fundamental driver of social, environmental, economic and industrial indicators of sustainable development. In Brazil, the chemicals industry's deficit has grown over the last three decades. Patents are important sources of information because patent documents contain 75% of all technological information available. The National Institute of Industrial Property in Brazil has created a Technology Observatory with the purpose of identifying and analyzing technological information contained in patent documents within the ambit of partnerships with government entities or business associations, in order to support their technology-related decision-making processes. The paper gives examples of ethanol and biotechnology patent documents, including pharmaceuticals, of which there are very few in Brazil. However, a few of the patent applications identified are filed in Brazil, giving the country the opportunity to transform this scientific knowledge into technology by means of partnership agreements with companies. Finally, the paper presents information on the patent applications filed by the world's leading chemicals companies as measured by their revenues, and the respective numbers of patent applications in the last five years in organic chemistry and polymers, sectors in which Brazil is currently dependent on imports for over 50% of its needs. The patent assignees in these sectors in Brazil are also identified, and the paper concludes that Brazil needs to invest in the development of professionals, providing clearly-defined career paths in technology innovation teams at R&D institutions, and to foster more initiatives such as the creation of a new research and innovation entity, EMBRAPII, since investing in science and technology is a prerequisite for knowledge production, industrial property, economic development and, consequently, the competitiveness of the country.

A teoria de pearson para a disciplina de química orgânica: um exercício prático e teórico aplicado em sala de aula

We report a didactic experience in teaching Pearson's theory (HSAB) to graduate students in organic chemistry. This approach was based on teaching students how to use computer programs to calculate frontier orbitals (HOMO-LUMO). The suggested level of calculation was a semi-empiric PM3, proving to be efficient for obtaining robust and fast numerical results that can be performed easily in the classroom. We described a practical computational exercise and asked students to compare these numerical data with qualitative analysis using valence bond theory. A comprehensive solution of this exercise is presented, aiming to support teachers in their lessons.

Mapas conceptuales como herramienta pedagógica en la enseñanza de la química orgánica

Organic Chemistry is a branch of Chemistry involving the study of the carbon atom, its compounds and reactions. Numerous investigations carried out in the field of teaching and learning processes indicate that knowledge of a conceptual and explanatory type is not conveyed in a conventional manner, but rather each individual is constructed. Therefore, the proposal for this study was devised to help students achieve significant sustainable learning in the area of reactivity in organic chemistry, using the Concept Maps described by Novak (1998) as a teaching tool.

Resgatando um método eficiente para determinação do ponto de ebulição de substâncias orgânicas: percolador versus Siwoloboff

The aim of this paper was to revive the accurate determination of the boiling point of organic compounds using the percolator technique developed in the 1960s. Although this method is simple, fast and efficient it is omitted from current textbooks. This method has several advantages over Siwoloboff such as high reproducibility and direct measurement of the boiling point of the sample obtained by observing the temperature of the vapor-liquid equilibrium. The experiments were performed in the organic chemistry laboratory but allow interdisciplinary integration with other disciplines of several academic areas.

Modulating the electronic structure of amino acids: interaction of model lewis acids with anthranilic acid

On the basis of theoretical B3LYP calculations, Yáñez and co-workers (J. Chem. Theory Comput. 2012, 8, 2293) illustrated that beryllium ions are capable of significantly modulating (changing) the electronic structures of imidazole. In this computational organic chemistry study, the interaction of this β-amino acid and five model Lewis acids (BeF1+, Be2+, AlF2(1+), AlF2+, and Al3+) were investigated. Several aspects were addressed: natural bond orbitals, including second order perturbation analysis of intra-molecular charge delocalization and the natural population analysis atomic charges; molecular geometries; selected infrared stretching frequencies (C-N, C-O, and N-H), and selected ¹H-NMR chemical shifts. The data illustrate that this interaction can weaken the H-O bond and goes beyond strengthening the intra-molecular hydrogen bond (N...H-O) to cause a spontaneous transfer of the proton to the nitrogen atom in five cases generating zwitterion structures. Many new features are observed. Most importantly, the zwitterion structures include a stabilizing hydrogen bond (N-H...O) that varies in relative strength according to the Lewis acid. These findings explain the experimental observations of α-amino acids (for example: J. Am. Chem. Soc. 2001, 123, 3577) and are the first reported fundamental electronic structure characterization of β-amino acids in zwitterion form.