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Submitted by Mírian Farias Ribeiro (mirianfribeiro@yahoo.com.br) on 2022-05-12T14:23:25Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Lara.pdf: 3239371 bytes, checksum: fe986173cc8ca5e31d3222e32cd76509 (MD5) Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2022-05-16T11:30:57Z (GMT) No. of bitstreams: 2 Lara.pdf: 3239371 bytes, checksum: fe986173cc8ca5e31d3222e32cd76509 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Made available in DSpace on 2022-05-16T11:30:57Z (GMT). No. of bitstreams: 2 Lara.pdf: 3239371 bytes, checksum: fe986173cc8ca5e31d3222e32cd76509 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-10-02 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES Neste trabalho, é descrita a síntese de calcogenetos vinílicos partindo de dialquinos ou de selenoalquinos. Através da reação de hidrocalcogenação utilizando como solvente polietilenoglicol-400 e o agente redutor hidreto de boro e sódio na presença de diinos conjugados 1a-b e dicalcogenetos de diorganoíla 2ae foi possível obter (Z)-1-organilcalcogeno-1,4-diorganilbut-1-en-3-inos 3a-h, em condições brandas com aquecimento de 30 °C. Já com aumento na temperatura reacional foram obtidos os (1Z,3Z)-1,4-diorganilcalcogeno-1,4-difenilbuta-1,3- dienos 4a-c. Este método simples e geral fornece os calcogenetos vinílicos preferencialmente com configuração Z através do uso de aquecimento convencional ou irradiação de micro-ondas. A partir de selenoalquinos 5a-j foi possível sintetizar selenetos vinílicos funcionalizados com imidazol 6. A síntesefoi realizada através da adição nucleofílica de imidazol em meio livre de aditivos usando N,N-dimetilformamida como solvente. Esta metodologia é regio- e estereosseletiva para a formação de novos selenetos vinílicos 7a-j exclusivamente de configuração Z. In this work, the synthesis of the vinyl chalcogenides starting from dialkynes or selanylalkynes is describe. In the hydrochalcogenation reaction polyethylene glicol-400 was used as solvent and the reducing agent sodium borohydride in the presence of conjugated dialkynes 1a-b and diorganyl dichalcogenides 2a-e to obtain (Z)-1-organylchalcogeno-1,4-diorganylbut-1-en-3-ynes 3a-h, under mild conditions at 30 °C. Moreover, (1Z,3Z)-1,4-bis(organylchalcogeno)-1,4- diphenylbuta-1,3-dienes 4a-c were obtained at higher temperatures. This general and simple method provides the vinyl chalcogenides preferably with Z configuration by using of conventional heating or microwave irradiation. From selenaylalkynes 5a-j was possible to synthesize functionalized imidazole vinyl selenides. The synthesis was carried out by nucleophilic addition of imidazole 6 in additive-free conditions using N,N-dimethylformamide as solvent. This methodology is regio- and stereoselective in getting new vinyl selenides 7a-j exclusively in Z configuration.

Submitted by Simone Maisonave (simonemaisonave@hotmail.com) on 2020-07-03T16:44:08Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese_Paloma_Cardoso_da_Rosa.pdf: 974689 bytes, checksum: f7a914dbd26d944a42b3b5b0626ce4fc (MD5) Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2020-07-07T01:26:17Z (GMT) No. of bitstreams: 2 Tese_Paloma_Cardoso_da_Rosa.pdf: 974689 bytes, checksum: f7a914dbd26d944a42b3b5b0626ce4fc (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Made available in DSpace on 2020-07-07T01:26:17Z (GMT). No. of bitstreams: 2 Tese_Paloma_Cardoso_da_Rosa.pdf: 974689 bytes, checksum: f7a914dbd26d944a42b3b5b0626ce4fc (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2013-04-17 Sem bolsa Neste trabalho foram sintetizados bis-arilseleno alquenos utilizando a base KF/Al2O3 e PEG-400 como solvente (Esquema 1). A metodologia proposta baseia-se nos princípios da química verde, através de um procedimento one-pot, a partir de alquinos terminais (1) e disselenetos de diarila (2), foram obtidos os respectivos bis-seleno alquenos de configuração Z (3) com bons rendimentos para oito exemplos, com substituintes aromáticos e alifáticos. Além disso, foi possível reduzir o tempo reacional utilizando irradiação de micro-ondas e reutilizar o sistema KF/Al2O3/PEG-400 sem tratamento prévio, mantendo sua atividade. In this paper bis-arylselene alkenes were synthesized using KF/Al2O3 as a base and PEG-400 as a solvent (Scheme 1). The methodology proposed is based on the principles of Green Chemistry, in which by a one-pot procedure from terminal alkynes (1) and diaryl diselenides (2), the corresponding bisselene alkenes of configuration Z (3) were obtained in good yields for eight examples, with aromatic and aliphatic substituents. Moreover, it was possible to reduce the reaction time by using microwave irradiation and reuse the KF/Al2O3/PEG-400 system without prior treatment while maintaining its activity.

Submitted by Mírian Farias Ribeiro (mirianfribeiro@yahoo.com.br) on 2022-05-11T13:25:09Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Borges.pdf: 2369615 bytes, checksum: 1d5d0aa1bb5256eccc3d937db04d350d (MD5) Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2022-05-16T11:20:29Z (GMT) No. of bitstreams: 2 Borges.pdf: 2369615 bytes, checksum: 1d5d0aa1bb5256eccc3d937db04d350d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Made available in DSpace on 2022-05-16T11:20:29Z (GMT). No. of bitstreams: 2 Borges.pdf: 2369615 bytes, checksum: 1d5d0aa1bb5256eccc3d937db04d350d (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2013-02-15 Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES No presente trabalho, PEG-400 foi utilizado como solvente verde para a síntese de vários bis-calcogenetos vinílicos em rendimentos que variaram de moderados a bons (30 a 83%) e alta seletividade. Este método simples e geral, envolve a reação de dicalcogenetos de diorganoila com calcogenoalquinos, utilizando como agente redutor o NaBH4 e fornecendo os bis-calcogenetos vinílicos preferencialmente com configuração Z (Esquema 1). In this work, PEG-400 was successfully used as a green solvent to synthesize several vinyl bis-chalcogenide in moderate to good (30 to 83%) and has in high selectivity. This general, simple and quite method involves a reaction of diorganoyl dichalcogenides with chalcogenealkynes, using NaBH4 resulting in the corresponding vinyl bis-chalcogenide preferentially with a Z configuration (Scheme 1).