729 research outputs found
Managing conflict in organisational change
Organisational change and conflict are two essential topics that engineering managers need to understand and have confidence in acting on, if they are to succeed in todays changing and increasingly competitive environment. This paper examines and dissects the elements of organisational change that almost inevitably result in conflict. Conflicts that impact on organisational change can act as a retardant to progress, creativity, innovation and productivity, and potentially precipitate the demise of an organisation. One of the many difficulties relating to organisational conflict is to define the division between conflict and competition. This paper explores what is known about the various states of conflict and presents an approach to addressing this problem, through identifying and subsequently managing institutional elements influencing organisational change and conflict
Speciation of Cobalt(II) complexes with succinic acid and L-glutamine in Tetra Butyl Ammonium Bromide – water mixtures
Speciation of cobalt(II) complexes with L-glutamine (Gln) and succinic acid (Suc) in varying concentrations (0.0-3.0%, w/v) of TBAB-water mixtures with pH-meter has been made at an ionic strength of 0.16 mol dm-3 and temperature 303 K using a Control Dynamics-APX 175E/C pH meter. Various models for the species of these ligards are refined by using the computer programs SCPHD and MINIQUAD75. The active forms of the Cobalt(II) are ML, ML2 and MLH for succinic acid and ML and ML2H for L-glutamine. The trend in the variation of protonation constants with dielectric constant is explained on the basis of electrostatic and non-electrostatic forces. The species distribution with pH at different solvent composition and the plausible equilibria for the formation of the species are also presented
The asymmetric synthesis of (+)-sitophilure, the natural form of the aggregation pheromone of Sitophilus oryzae L. and Sitophilus zeamais M.
The asymmetric synthesis of (+)-sitophilure, the aggregation pheromone of Sitophilus oryzae L. and Sitophilus zeamais M., was carried out in 12 steps, 18% overall yield and 82% enantiomeric excess from the enzymatic reduction of methyl 3-oxopentanoate with S. cerevisiae in the presence of ethyl chloroacetate.A forma natural do (+)-sitofilure, feromônio de agregação de Sitophilus oryzae L. e Sitophilus zeamais M., foi preparada em 12 etapas, 18% de rendimento total e 82% de excesso enantiomérico a partir da redução microbiológica de 3-oxopentanoato de metila com S. cerevisiae na presença de cloroacetato de etila.363368Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Organic synthesis: new vistas in the brazilian landscape
FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOIn this overview, we present our analysis of the future of organic synthesis in Brazil, a highly innovative and strategic area of research which underpins our social and economical progress. Several different topics (automation, catalysis, green chemistry9011895941FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO2013/07607-82016/08569-02017/06836-42016/12541-4sem informaçãoThis work is dedicated to all the past and current chemists who have contributed to the advancement of the field of chemical synthesis in Brazil. The authors are affiliated to OCRC - Obesity and Comorbidities Research Center supported by Fundação de Ampa
The asymmetric total synthesis of (+)- and (-)-trypargine via Noyori asymmetric transfer hydrogenation
A concise and efficient total synhesis of (+)- and (-)-trypargine (6 steps and 38% overall yield), a 1-substituted β-carboline guanidine alkaloid isolated from the skin of the African frog K. senegalensis, was developed based on the construction of the β-carboline moiety via Bischler-Napieralski reaction and the enantioselective reduction of the dihydro-β-carboline intermediate via an asymmetric transfer hydrogenation reaction using Noyori's protocol.Uma síntese total e eficiente da (+) e (-)-tripargina, alcalóide β-carbolínico isolado da pele da rã africana K. Senegalensis, foi realizada em 6 etapas e 38% de rendimento global, a partir da triptamina, tendo como base a construção do sistema β-carbolínico via reação de Bischler-Napieralski e a redução enantiosseletiva do intermediário diidro-β-carbolínico via reação de transferência de hidrogênio assimétrica usando o protocolo de Noyori.14341440Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq
Computer-guided total synthesis of natural products: recent examples and future perspectives
FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOQuantum chemical calculations of nuclear magnetic resonance (NMR) shifts and coupling constants have been extensively employed in recent years mainly to facilitate structural elucidation of organic molecules. When the results of such calculations are used29510411075FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO2013/07607-82014/25474-82016/12541-4The authors are grateful to FAPESP (grants 2013/07607-8, 2014/25474-8 and 2016/12541-4) and CONICET, ANPCyT and UNR for financial suppor
One-pot synthesis of organophosphate monoesters from alcohols
AbstractA one-pot procedure for the phosphorylation of alcohols provides the corresponding phosphate monoesters in improved yields. The protocol features the use of tetrabutylammonium hydrogen phosphate and trichloroacetonitrile, followed by purification of the crude product by flash chromatography on silica gel. The final step, cation exchange chromatography, affords the organophosphates as ammonium salts that are usually required for biochemical applications. The mechanism appears to be phosphate rather than alcohol activation by trichloroacetonitrile
Enantioselective approach to the asymmetric synthesis of (6R)-hydroxymethyl-5,6-dihydro-2H-pyran-2-one. A formal synthesis of (R)-argentilactone and total synthesis of (R)-goniothalamin
The asymmetric synthesis of the (6R)-hydroxymethyl-5,6-dihydro-2H-pyran-2-one, a key intermediate in the formal synthesis of (R)-argentilactone, and the total synthesis of ( R)goniothalamin are described. Our aproach involved the Lemieux-Johnson oxidative cleavage, enantioselective Keck allylation, ring-closing metathesis and Wittig olefination.1011812
Total Synthesis and Structural Validation of Phosdiecin A via Asymmetric Alcohol-Mediated Carbonyl Reductive Coupling
The first total synthesis and structural validation of phosdiecin A was accomplished in 13 steps through asymmetric iridium-catalyzed alcohol-mediated carbonyl reductive coupling. The present route is the shortest among >30 total and formal syntheses of fostriecin family members.Fil: Della Felice, Franco. Universidade Estadual de Campinas; Brasil. University of Texas at Austin; Estados UnidosFil: Sarotti, Ariel Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario. Instituto de Química Rosario. Universidad Nacional de Rosario. Facultad de Ciencias Bioquímicas y Farmacéuticas. Instituto de Química Rosario; ArgentinaFil: Krische, Michael J.. University of Texas at Austin; Estados UnidosFil: Pilli, Ronaldo A.. Universidade Estadual de Campinas; Brasi
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