title: Solid catalysts for multistep reactions: one-pot synthesis of 2,3-dihydro-1,5-benzothiazepines with solid acid and base catalysts.
abstract: 1,5-Benzothiazepines derivatives were obtained first by starting from 1,3-diphenylpropenone derivatives (chalcones) and 2-aminothiophenol by using aluminosilicate solid catalysts. However, diffusional limitations and the strong adsorption of products on the catalyst are deleterious for catalyst activity and life. Then a structured amorphous mesoporous catalyst with large pores and mild acidity that works at higher temperatures allowed us to obtain high conversions (99 %) and selectivities (98 %) of the desired product. A one-pot synthesis of 1,5-benzothiazepines that starts from benzaldehyde, acetophenone, and 2-aminothiophenol with 95 % yield was performed by combining optimized solid base and acid catalysts in batch mode as well as in a continuous-flow reactor system. Much better conversion and selectivity as well as process intensification has been achieved with the structured mesoporous materials by avoiding intermediate and final neutralization and purification steps required in the synthesis reported previously that uses homogeneous catalysts.
authors.affiliation: Instituto de Tecnología Química (UPV-CSIC), Universitat Politécnica de València, Avda dels Tarongers s/n, 46022, Valencia (Spain), Fax: (+34) 963877809. acorma@itq.upv.es.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Climent
authors.forename: Avelino
authors.initials: A
authors.lastname: Corma
authors.forename: Sara
authors.initials: S
authors.lastname: Iborra
authors.forename: Laura
authors.initials: L
authors.lastname: Martí
mesh_terms: D000327:Adsorption; D002384:Catalysis; D060326:Chemistry Techniques, Synthetic; D004058:Diffusion; D006863:Hydrogen-Ion Concentration; D013841:Thiazepines / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: C106746:1,5-benzothiazepine; D013841:Thiazepines
keywords: cyclization; heterocycles; heterogeneous catalysis; mesoporous materials; multicomponent reactions