Cyclic carbonate synthesis from CO2and epoxides using zinc(II) complexes of arylhydrazones of β-diketones

Zinc(II) complexes of arylhydrazones of β-diketones (AHBD) were used for the first time as catalysts combined with tetrabutylammonium bromide (TBABr), in the coupling reaction between CO2 and epoxides. The influence of pressure and temperature on cyclic carbonate formation was investigated, as well as the catalytic activity toward different substrates (e.g. styrene oxide, propylene oxide and cyclohexene oxide). The molar ratio between metal complex and TBABr was determined for maximum catalytic activity

Resultados funcionais e sobrevida de pacientes com câncer de cavidade oral e orofaringe submetidos à glossectomia total

Made available in DSpace on 2019-09-11T20:51:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2019Introduction: Cancer of the oral cavity and oropharynx exhibits an aggressive behavior and its diagnosis is, in most cases, attained at advanced stages. Total glossectomy is a therapeutic option in locally advanced cancer, and the only choice in the presence of recurrent or residual disease after chemoradiotherapy. Objective: To evaluate the clinical-epidemiological profile, postoperative complications, survival rates and functional aspects of patients with oral cavity and oropharynx cancer after total glossectomy. Methods: This was a retrospective study that included 22 patients with oral cavity and oropharyngeal cancer after total glossectomy. Results: All patients were males, with a median age of 57 years. Most of tumors were located in the tongue and mouth floor and classified as stage IVa. Total glossectomy as the initial treatment was performed in 18 patients and as a salvage operation in four patients. The major pectoralis myocutaneous flap was used for reconstruction in all cases. The main postoperative complications were wound infections and salivary fistula. Conclusion: Overall survival was 19% and cancer-specific survival was 30.8% in 5 years. Eight patients were rehabilitated for exclusive oral feeding without the dependence on tracheostomy and enteral tube, all with an overall survival greater than 15 months. © 2019 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-FacialQuinsan, I.D.C.M., Universidade de Taubaté (UNITAU), Taubaté, SP, BrazilCosta, G.C., Universidade de Taubaté (UNITAU), Taubaté, SP, BrazilPriante, A.V.M., Universidade de Taubaté (UNITAU), Taubaté, SP, BrazilCardoso, C.A., Universidade de Taubaté (UNITAU), Taubaté, SP, BrazilNunes, C.L.S., Hospital Regional do Vale do Paraíba (HRVP), Taubaté, SP, Brazi

CO2 + ionic liquid biphasic system for reaction/product separation in the synthesis of cyclic carbonates

The possibility of using supercritical CO2 (scCO2) technology as a second step for extracting propylene carbonate produced from the coupling reaction between propylene oxide and CO2, was investigated. The coupling reaction was performed under biphasic gas-liquid conditions, using a zinc(II) complex of arylhydrazones of β-diketones (Zn(II)-AHBD) as metal catalyst, combined with tetrabutylammonium bromide (TBABr). 1-Ethyl-3-methylimidazolium ethyl sulfate ([EMIM][EtSO4]) and methyltrioctylammonium chloride ([ALIQUAT][Cl]) were explored as reaction solvents, in order to efficiently solubilize the catalyst and retain the catalyst inside the reactor during the product extraction step. Results obtained were compared with other common used solvents as methyl ethyl ketone (MEK), ethyl lactate (EL), and polyethylene glycol 400 (PEG 400). [ALIQUAT][Cl] was selected as the most promising solvent and scCO2 extraction was effectively applied as a second step to isolate propylene carbonate from the catalyst system. Following this strategy, the catalyst system was reused three times, without loss of activity. © 201

CO2 + ionic liquid biphasic system for reaction/product separation in the synthesis of cyclic carbonates

The possibility of using supercritical CO2 (scCO2) technology as a second step for extracting propylene carbonate produced from the coupling reaction between propylene oxide and CO2, was investigated. The coupling reaction was performed under biphasic gas-liquid conditions, using a zinc(II) complex of arylhydrazones of β-diketones (Zn(II)-AHBD) as metal catalyst, combined with tetrabutylammonium bromide (TBABr). 1-Ethyl-3-methylimidazolium ethyl sulfate ([EMIM][EtSO4]) and methyltrioctylammonium chloride ([ALIQUAT][Cl]) were explored as reaction solvents, in order to efficiently solubilize the catalyst and retain the catalyst inside the reactor during the product extraction step. Results obtained were compared with other common used solvents as methyl ethyl ketone (MEK), ethyl lactate (EL), and polyethylene glycol 400 (PEG 400). [ALIQUAT][Cl] was selected as the most promising solvent and scCO2 extraction was effectively applied as a second step to isolate propylene carbonate from the catalyst system. Following this strategy, the catalyst system was reused three times, without loss of activity. © 201