Affiliation:
1. Departamento de Química Orgánica, Facultad de Ciencias Químicas Universidad Nacional de Córdoba X5000HUA Córdoba Argentina
2. Instituto de Investigaciones en Fisicoquímica de Córdoba-INFIQC-CONICET- Universidad Nacional de Córdoba Haya de La Torre y Medina Allende, Ciudad Universitaria X5000HUA Córdoba Argentina
3. Departamento de Ciencias Químicas, Facultad de Farmacia y Bioquímica Universidad de Buenos Aires C1113AAD Ciudad Autónoma de Buenos Aires Argentina
4. Instituto Química y Metabolismo del Fármaco IQUIMEFA-UBA-CONICET Junín 956 C1113AAD Ciudad Autónoma de Buenos Aires Argentina
Abstract
AbstractIn this work, the synthesis and characterization of a heterogeneous photocatalyst based on spherical silica nanoparticles superficially modified with anthraquinone 2‐carboxylic acid (AQ−COOH) are presented. The nanomaterial was characterized by TEM, SEM, FT‐IR, diffuse reflectance, fluorescence, NMR, DLS, XRD and XPS. These analyses confirm the covalent linking of AQ−COOH with the NH2 functionality in the nanomaterial and, more importantly, the photocatalyst retains its photophysical properties once bound. The heterogeneous photocatalyst was successfully employed in the aerobic hydroxylation of arylboronic acids to phenols under sustainable reaction conditions. Phenols were obtained in high yields (up to 100 %) with low catalyst loading (3.5 mol %), reaching TOF values of 3.7 h−1. Using 2‐propanol as solvent at room temperature, the visible light photocatalysis produced H2O2 as a key intermediate to promote the aerobic hydroxylation of arylboronic acids. The heterogeneous photocatalyst was reused at least 5 times, without modification of the nanomaterial structure and morphology. This simple heterogeneous system showed great catalytic activity under sustainable reaction conditions.
Funder
Fondo para la Investigación Científica y Tecnológica
Consejo Nacional de Investigaciones Científicas y Técnicas
Subject
General Chemistry,Catalysis,Organic Chemistry