INVESTIGADORES
SATHICQ Angel Gabriel
artículos
Título:
New Vanadium Keggin Heteropolyacids Encapsulated in a Silica Framework: Recyclable Catalysts for the Synthesis of Highly Substituted Hexahydropyrimidines Under Suitable Conditions
Autor/es:
VALERIA PALERMO; A. G. SATHICQ; T. CONSTANTIEUX; JEAN RODRIGUEZ; P. VAZQUEZ; G. ROMANELLI
Revista:
CATALYSIS LETTERS
Editorial:
SPRINGER
Referencias:
Lugar: Berlin; Año: 2015
ISSN:
1011-372X
Resumen:
Solid acid catalysts based on the direct incorporation of the vanadium Keggin heteropolyacid (PMo11V) structure during the synthesis of silica by the sol-gel technique, in acidic media using tetraethyl orthosilicate (PMo11VSiO21, PMo11VSiO22, PMo11VSiO23, and PMo11VSiO24), were prepared and characterized by 31P-NMR, FT-IR, XRD, and textural properties (SBET). The acidic characteristics of the catalysts were determined by potentiometric titration with n-butylamine. A series of highly substituted hexahydropyridines were synthesized using these new materials, encapsulated in a silica framework, as catalyst in solvent-free conditions. This methodology requires short reaction time (1.5 h), a temperature of 80 ºC in solvent freeconditions to obtain good to excellent yields of trifluoromethyl-hexahydropyrimidine derivatives. The Keggin catalyst embedded in the silica matrix is insoluble in polar media, which allows easy removal of the reaction products without affecting their catalytic activity.