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Reação de condensação do glicerol com compostos carbonílicos : síntese, caracterização e aplicação em cristais líquidos

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Reação de condensação do glicerol com compostos carbonílicos : síntese, caracterização e aplicação em cristais líquidos

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Título Reação de condensação do glicerol com compostos carbonílicos : síntese, caracterização e aplicação em cristais líquidos
Outro título Condensation reaction of glycerol and carbonyl compounds : synthesis, characterization, and derivatization for liquid crystals
Autor Kautz, Jacqueline
Feltrin, Carlos Willian
Sales, Eric Souza
Eifler-Lima, Vera Lucia
Merlo, Aloir Antonio
Abstract Condensation reactions of glycerol with aldehydes and ketones were performed under thermal heating and microwave irradiation regimes. Homogeneous and heterogeneous catalysts were tested in both conditions. A silica sulfated (SiO2–SO3H) heterogeneous catalyst demonstrated the best performance relative to a selectivity of >95% in favor of 5-membered ketals. For acetals, preference in favor of 5-membered or 6-membered functional groups depends on the nature of the catalyst. Homogenous catalysts favor the more stable 6-membered acetals, whereas heterogeneous catalysts favor the less stable 5-membered acetals. However, the isomer ratios in the acetalization reaction are too low, and hence the reaction cannot be used in a synthetic plan for functional materials. Ketalization processes mediated by SiO2–SO3H show a high selectivity in favor of a 5-membered ring (1,3-dioxolane). The scope of condensation was tested with different ketones. A mechanism for heterogeneous catalysis related to the selectivity in the cyclization process is presented herein. Solketal, a commercial product, was also obtained by a condensation reaction of glycerol and propanone, and showed a high selectivity in favor of 1,3-dioxolane. It was transformed to potential allylic and chiral intermediates. A mesogenic core was connected to the organic framework of glycerol to produce a monomer liquid crystal material with a stable smectic-C mesophase.
Contido em Química nova. São Paulo. Vol. 38, n. 8 (set. 2015), p. 1053-1062
Assunto Compostos carbonílicos
Condensação
Cristais liquidos
Glicerol
[en] Condensation reaction
[en] Glycerol derivatives
[en] Heterogeneous catalyst
[en] Liquid crystals
[en] Solketal transformation
Origem Nacional
Tipo Artigo de periódico
URI http://hdl.handle.net/10183/131116
Arquivos Descrição Formato
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