Preparation of aromatic geraniol analogues via a Cu(I)-mediated Grignard coupling

Difunctional allylic terpenes are important synthetic building blocks. Functionalization of protected geranyl derivatives by SeO2/t-BuO2H adsorbed on SiO2 provides a convenient route to such compounds. The chosen protecting groups clearly influence the oxidation process. Also, an efficient synthesis of 2-geranylphenol derivatives via a Cu(I)-mediated Grignard coupling of 2-lithiophenols and geranyl substrates was developed.Terpenos alílicos difuncionais constituem-se em importantes blocos de construção sintéticos. A funcionalização de derivados geranílicos protegidos por SeO2/t-BuO2H adsorvido em SiO2, propicia uma rota conveniente para tais compostos. Os grupos protetores escolhidos efetivamente influenciam o processo de oxidação. Também, desenvolveu-se uma eficiente síntese de derivados 2-geranilfenóis através de um acoplamento de Grignard mediado por Cu(I) entre derivados de 2-lítiofenóis e substratos geranílicos.975981Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Global mindset and the internationalization of small firms: The importance of the characteristics of entrepreneurs

Despite being a relatively new concept, the importance of the global mindset is already well-documented. So far research has primarily focused on multinational companies and therefore the operationalization of the concept is still a work in progress. Recognizing the importance of entrepreneurs in small companies, yet mindful of the gaps that exist, this paper addresses the factors that constitute the global mindset and their influence on the internationalization of small Portuguese companies. Using information-processing theory through a quantitative, surveybased study and Structural Equation Modeling (SEM), the results show the importance of the characteristics of both entrepreneurs and firms in explaining the global mindset, and confirm the impact they have on internationalization behavior. The entrepreneur’s level of education, their satisfaction with company performance in the domestic market and the potential for growth in the domestic market all affect the global mindset model. The conclusions are useful for entrepreneurs and national authorities aiming to successfully implement internationalization practices, given the role of the global mindset in exploring global business opportunities and in the global success of companies. Replication of the research in different contexts is essential for the wider generalization of the results.info:eu-repo/semantics/publishedVersio

Chiral Pharmaceutical Intermediaries Obtained by Reduction of 2-Halo-1-(4-substituted phenyl)-ethanones Mediated by Geotrichum candidum CCT 1205 and Rhodotorula glutinis CCT 2182

Enantioselective reductions of p-R1-C6H4C(O)CH2R2 (R1 = Cl, Br, CH3, OCH3, NO2 and R2 = Br, Cl) mediated by Geotrichum candidum CCT 1205 and Rhodotorula glutinis CCT 2182 afforded the corresponding halohydrins with complementary R and S configurations, respectively, in excellent yield and enantiomeric excesses. The obtained (R)- or (S)-halohydrins are important building blocks in chemical and pharmaceutical industries

Cross-cultural analysis of the global mindset and the internationalization behavior of small firms

This research analyzes the influence of a global mindset on the internationalization behavior of Norwegian and Portuguese small firms. It specifically sets out to assess the role of global orientation of the entrepreneur and firm perspectives on the global market. Based on a sample of 354 small firms, we used structural equation modeling to conduct our analysis. The results show the differing importance of a range of factors in explaining global mindset in different contexts. The global mindset of Norwegian entrepreneurs conditions their behavior and international experience, while for Portuguese entrepreneurs it affects the cognitive domain and their technical expertise. Global mindset and global orientation have more relevant effects on the internationalization behavior of Norwegian firms than that of Portuguese firms.info:eu-repo/semantics/publishedVersio

Reaction of aromatic azides with strong acids: formation of fused nitrogen heterocycles and arylamines

We describe in this paper the action of trifluoroacetic acid, trifluoromethanesulfonic acid and aluminum chloride upon ortho-substituted aryl azides to form indoles, azepines and arylamines in good yields. The protonated azides lose nitrogen to form arylnitrenium ion intermediates which undergo intramolecular aromatic N-substitution. The acid decomposition of aryl azides is compared with reported thermolyses.Descrevemos neste trabalho a ação de ácido trifluoroacético, ácido trifluorometanossulfônico e cloreto de alumínio sobre aril azidas orto-substituídas para formar indóis, azepinas e arilaminas com bons rendimentos. As azidas protonadas perdem nitrogênio para formar íons arilnitrênios intermediários que sofrem N-substituição aromática intramolecular. A decomposição ácida de aril azidas é comparada com resultados de termólise tomados da literatura.415420Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Effect Of Immobilized Cells In Calcium Alginate Beads In Alcoholic Fermentation.

Saccharomyces cerevisiae cells were immobilized in calcium alginate and chitosan-covered calcium alginate beads and studied in the fermentation of glucose and sucrose for ethanol production. The batch fermentations were carried out in an orbital shaker and assessed by monitoring the concentration of substrate and product with HPLC. Cell immobilization in calcium alginate beads and chitosan-covered calcium alginate beads allowed reuse of the beads in eight sequential fermentation cycles of 10 h each. The final concentration of ethanol using free cells was 40 g L-1 and the yields using glucose and sucrose as carbon sources were 78% and 74.3%, respectively. For immobilized cells in calcium alginate beads, the final ethanol concentration from glucose was 32.9 ± 1.7 g L-1 with a 64.5 ± 3.4% yield, while the final ethanol concentration from sucrose was 33.5 ± 4.6 g L-1 with a 64.5 ± 8.6% yield. For immobilized cells in chitosan-covered calcium alginate beads, the ethanol concentration from glucose was 30.7 ± 1.4 g L-1 with a 61.1 ± 2.8% yield, while the final ethanol concentration from sucrose was 31.8 ± 6.9 g L-1 with a 62.1 ± 12.8% yield. The immobilized cells allowed eight 10 h sequential reuse cycles to be carried out with stable final ethanol concentrations. In addition, there was no need to use antibiotics and no contamination was observed. After the eighth cycle, there was a significant rupture of the beads making them inappropriate for reuse.33

Interactions and scattering of quantum vortices in a polariton fluid

Quantum vortices, the quantized version of classical vortices, play a prominent role in superfluid and superconductor phase transitions. However, their exploration at a particle level in open quantum systems has gained considerable attention only recently. Here we study vortex pair interactions in a resonant polariton fluid created in a solid-state microcavity. By tracking the vortices on picosecond time scales, we reveal the role of nonlinearity, as well as of density and phase gradients, in driving their rotational dynamics. Such effects are also responsible for the split of composite spin-vortex molecules into elementary half-vortices, when seeding opposite vorticity between the two spinorial components. Remarkably, we also observe that vortices placed in close proximity experience a pull-push scenario leading to unusual scattering-like events that can be described by a tunable effective potential. Understanding vortex interactions can be useful in quantum hydrodynamics and in the development of vortex-based lattices, gyroscopes, and logic devices.Comment: 12 pages, 7 figures, Supplementary Material and 5 movies included in arXi

Tailor made degradable ureteral stents from natural origin polysaccharides

A urinary stent is defined as a thin tube, which is inserted in the ureter to prevent or treat the obstruction of urine flow from the kidney. Silicone, latex, polyvinylchloride and polyurethanes are the most widely used materials for the preparation of stents. Nonetheless, severe clinical complications may result from the use of these materials such as fracture, encrustation and infection. In some of the cases, the ureteral stents are temporary and it is often required a second surgery to remove the stent. The main complications with ureteral stents are dislocation, infection, and blockage by encrustation [1]. Recently, a tendency has been noticed favouring less invasive approaches (e.g. pharmacological or catheterization) in treating patients who exhibit symptoms or signs of urinary retention [2]. Currently, nearly 100% of the people who have an urological stent are likely to develop a bacterial infection within 30 days, which increases morbidity threefold [1]. Different types of temporary and permanent stents have been introduced into urological practice to relieve obstructions [3]. Particular attention should be devoted to polymers as they represent a highly versatile class of materials. Despite the fact that silicon continues to be the gold standard material for urological stents, there have been fast developments in manufacturing processes, as well as the introduction of new biodegradable materials in order to overcome the drawbacks of the available products. Polyurethane continues to be the most widely used material for polymeric stents; however it frequently promotes biofilm formation and bacterial adhesion leading to severe infections [2]. The concerns regarding existing stents are the motivation to design new biodegradable urological stent systems based on natural polymers, specifically polysaccharides, which present inherent biocompatibility, anti-bacterial properties and that can be tailor-made into a custom suitable stent for a particular patient

Recent Advances in the Biocatalytic Asymmetric Reduction of Acetophenones and α.β-Unsaturated Carbonyl Compounds

Whole cells of living organisms, mainly of yeasts, have been used as reliable biocatalysts by synthetic organic chemists to perform redox reactions of various functional groups. This review focuses on the potential of these whole cells to reduce acetophenones and α.β-unsaturated carbonyl compounds (aldehydes and ketones) furnishing relevant chiral building blocks for fine chemicals and the pharmaceutical industries