Seleção de sistemas liquidos bifasicos para a reciclagem de catalisadores homogeneos de Pd e Rh

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

Homogeneous catalysis with transition metal complexes displays disadvantages related to separation of products and catalysts, wich have generated a variety of efforts towards the development of new recycling procedures, mostly using biphase systems. The aim of this work was the application of liquid biphasic systems to accomplish product/catalyst separation in Pd-catalyzed Suzuki reaction and Rh-catalyzed hydroformylation reaction. The use of the biphasic system composed by dioxane + ethylene glycol + heptane in Pd-catalyzed Suzuki reaction caused deactivation of the catalyst during the first reaction, impeding attempts to its recycling. Moreover, significant losses of metal and phosphine to the extracting phase were observed with this biphasic system. With the biphasic system composed by THF + PEO 600 + heptane, it was possible to perform 5 recyclings of the catalyst for hydroformylation of styrene. However, the significant loss of metal caused a marked reduction in substrate conversion along the recycling procedures.

ASSUNTO(S)

reciclagem catalisadores

ACESSO AO ARTIGO

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