Palladium and palladium-gold containing siliceous-MCM-41 and sol-gel palladium and palladium-gold silica composites have been prepared. The catalytic performance of incorporated Pd/MCM-41, Au-Pd/MCM-41 and Pd and Au-Pd/SiO2 sol-gel catalysts for the Suzuki-Miyaura cross-coupling reaction was determined and the influence of the matrix and the catalyst composition on the catalytic activity were also studied. The catalysts were characterized by N-2 physisorption (BET/BJH methods), X-ray diffraction, temperature programmed reduction analysis, H-2 chemisorption, atomic absorption spectrophotometry and Raman spectroscopy. The silica-containing palladium and palladium-gold catalysts prepared using the MCM-41 matrix showed greater catalytic activity than using the conventional sol-gel method; however, gold had a significant influence on this reaction. The catalyst did not undergo metal leaching and could be easily recovered and re-used (reused). (C) 2013 The Authors. Published by Elsevier B.V. All rights reserved.
Based on Science, Technology & Innovation (ST&I) indicators, Brazil is a competitive and interesting country from the point of view of technological foreign investment. However, it is still incipient with regard to national investments, production of technological knowledge, inbound mobility of scientists and technology transfer to the productive sector. Among many other factors, global patent production is considered as an important indicator of innovation. Likewise, the balance between revenue and expenses obtained through royalties and licensing fees of technologies is also critical in mapping the diffusion and absorption of knowledge. The understanding of intellectual property and its strategic management brings a significant advantage to the economic and technological development of nations, especially in the field of chemistry, which greatly contributes to biotechnology, new materials and microelectronics - three fundamental areas for innovation in developed countries. Therefore, this article aims to map out competencies in chemistry in Brazil and evaluate science, technology and innovation indicators in the country, comparing this dynamic to the one of other BRIC members (Russia, India and China). Chemistry is the fourth biggest field of interest in Brazil based on the number of researchers registered at the governmental platform for researchers, Plataforma Lattes/CNPq, and is preceded by education, medicine and agronomy. The majority of research groups are registered in the area of materials, followed by macromolecules and polymers, pharmaceutical products and basic materials chemistry. These groups represent approximately 77% of research groups analyzed, therefore, indicating a tendency in the country. The analyses of patents in different sub-areas of chemistry reveal that non-residents file most deposits in the country, a probable reflection of the low internal intellectual property culture. Pharmaceutics and Fine Chemistry are prominent areas in the country, in line with the global trend. Among BRIC countries, China has the highest number of patents and of requests for protection in international offices. On the other hand, Brazil has the lowest number of chemical patents published at USPTO, EPO and JPO. An analysis of the transfer of technology data indicates an increase in this activity in various sub-areas of chemistry in the country. Despite the great efforts made by the country to consolidate its national innovation system, more needs to be done to put Brazil in a competitive position. In a globalized world dominated by large players, Brazil needs a lot of progress on ownership and generation of chemistry technologies to strengthen its national sovereignty. It is essential to strengthen chemical research at all levels, from elementary school to university, as an inexhaustible source of knowledge and technology that, when properly protected, may generate real public achievement and social return.
This work reports the functionalization of monoterpenoids with 2-iodo-1-methyl-1H-imidazole using Sonogashira cross-coupling reactions. Natural monoterpenes were also modified to obtain the corresponding alkynes which were used in the cross-coupling step. After a sequence of cross-coupling-hydrogenation-N-alkylation-ion metathesis, novel ionic liquids were obtained in reasonable yields. The obtained products can be used as scaffolds for the further synthesis of new ionic liquids derived from terpenoids and for new, potentially bioactive materials, e. g. polycyclic monocationic scaffolds. All obtained products show the characteristics of a room temperature ionic liquid (RTIL).
DESMYSTIFYING PATENT PROTECTION IN UNIVERSITIES. Brazilian universities and research institutions still fail to protect the knowledge and technology produced by their community of students, staff and professors while Intellectual Property (IP) issues along with the role of patents and their strategic management in educational and research institutions remain taboo or misunderstood. The focus of this work was to demystify these subjects, including IP, patents and their requirements, the decision to patent as well as tips for successful patenting. Any student, professor or researcher of an educational or research institution can invent and protect their technology. This paper shows how to make such a patent application.
FROM AROMAS AND PERFUMES, THE MARKET OF THE "SMELL" INDUSTRY. Several flavors and fragrances (F&F) companies hold the economic leadership in the market, although not always have also the leadership in patent applications. The ranking of technological production in the fragrance area still remains with industries while scientific knowledge is equally shared between industries and academia. Contextualizing Brazil in this scene, despite all scientific expertise gained over the years, brazilian technological park is still at the beginning of the production of technologies applied directly to the F&F industries. The dependence on foreign technologies is remarkable as indicated by the great trade deficit in this sector.
A chloride-free Pd(OAc)(2)/Cu(OAc)(2) system catalyzes the oxidation of organic substrates by molecular oxygen in nonacidic methanol solutions. Terminal olefins, i.e., 1-hexene, 1-octene, styrene, and 2-vinylnaphthalene, give the corresponding methyl ketones without a significant double-bond isomerization of long-chain substrates. The catalyst also promotes an unusual allylic oxidation of sterically encumbered trisubstituted internal double bonds in acyclic polyenes able to form eta(2)-eta(2)-chelates with palladium. Linalool and nerolidol, mono- and sesquiterpenic allylic alcohols, give corresponding allylic ethers arising from the exclusive oxidation of the internal double bonds. Monosubstituted terminal double bonds in both substrates remain intact due to the deactivating effect of the allylic hydroxyl group. Dihydromyrcene, a nonfunctionalized monoterpenic diene, gives allylic ether and methyl ketone arising from the oxidation of both trisubstituted and terminal double bonds, respectively. On the other hand, internal double bonds in the substrates without a terminal olefinic bond, such as citronellol, citronellal, nerol, and citral, do not undergo oxidation under similar conditions. A steric possibility for chelation of the terminal and internal double bonds on the same palladium atom seems to be a crucial factor to determine the reactivity of the internal double bonds in these substrates toward oxidation. The presence of the second eta(2)-coordinated double bond in these chelates favors the activation of the allylic C-H bond of the olefin, which results in eta(3)-allyl intermediates and, then, in allylic ethers. Nerol, a primary allylic alcohol, is oxidized to (Z)-citral, although the process is complicated by further nonselective transformations of citral. All oxygenated terpenic derivatives obtained in the present work have a pleasant scent with a flower or fruit tinge and are potentially useful as components of synthetic perfumes.
Linalool, a monoterpenic allylic alcohol, has been efficiently and selectively oxidized by dioxygen in methanol and ethanol solutions using a chloride-free Pd(OAc)(2)/Cu(OAc)(2) catalytic system under nonacidic conditions. Corresponding allylic ether arising from the exclusive oxidation of a trisubstituted internal double bond has been characterized as a major product in each alcohol. In methanol, this product, 7-methoxyhotrienol, was obtained in virtually quantitative yield. It is remarkable that a monosubstituted terminal double bond of the substrate remains intact. In acetic acid, catalytic palladium turnover was achieved only by using benzoquinone as a terminal oxidant, with the regioselectivity of allylic oxidation being completely switched from that in alcohols. A major product is 8-linalyl acetate, formed with up to 85% selectivity. All linalool derivatives obtained have a pleasant scent with a flower or fruit tinge and are natural products found either in exotic plants or in grape wines. To the best of our knowledge, the present work reports a first synthesis of these functionalized monoterpenes, potentially useful as components of synthetic perfumes. On the basis of the results obtained, the mechanism of this unusual oxidation reaction involving the formation of various organometallic intermediates is discussed, with bimetallic Pd-Cu catalysis being suggested.
The hydrogenation of myrcene catalyzed by Ru, Cr, Ir and Rh complexes leads to the formation of a complex mixture of mono-, di- and trihydrogenated products. Seven major products have been characterized, showing that they arise from the sigma-alkyl and/or eta(3)-allyl intermediates formed by the reaction of metal catalysts with both terminal C=C bonds of myrcene. A good control of chemoselectivity has been achieved through the appropriate choice of the metal and reaction conditions. Monohydrogenated products have been obtained with excellent combined selectivity of 95-98% at a high conversion of myrcene (> 80%). Among the catalysts studied, rhodium complexes show the highest activity and selectivity, especially at temperatures lower than 100 degrees C. (c) 2005 Elsevier B.V. All rights reserved.
Sol-gel palladium silica composites are active catalysts for the selective hydrogenation of myrcene. The temperature of the thermal treatment of the catalyst is essential for its selectivity. Catalysts treated at 1100 degrees C give monohydrogenated products with excellent combined selectivity of 90-95% at almost complete conversion of the substrate. The obtained products arise from the or-alkyl and/or eta(3)-allyl intermediates formed by the interaction of the palladium catalyst with both terminal C=C bonds of myrcene and the main products (ca. 70%) result from the reaction with the less substituted one. The selective monohydrogenation of myrcene could be useful to produce a mixture of diolefins of different reactivity, which could be further transformed to oxygenated derivatives with selectivities better than myrcene itself. (c) 2005 Elsevier B.V All rights reserved.