Chromium(III)-salen complex nanoparticles on AlPO4: as an efficient heterogeneous and reusable nanocatalyst for mild synthesis of highly functionalized piperidines, 2-arylbenzimidazoles, and 2-arylbenzothiazoles

• DOI: 10.1007/s13738-017-1097-x
• Publication Date: 2017-04-17T04:58:47Z
• Authors: Hashem Sharghi; Mahdi Aberi; Mohammad Mahdi Do...; Pezhman Shiri
• Keywords: 01 natural sciences; 7. Clean energy; 0104 chemical sciences

A simple, convenient, and highly efficient multicomponent one-pot synthesis of highly functionalized piperidines has been developed via tandem reactions of β-keto esters, aromatic aldehydes, and various amines in ethanol at room temperature using catalytic amount (10 mol%) of a chromium(III)-salen complex nanoparticles supported on AlPO4. The heterogeneous catalyst exhibited excellent activity and reusability (up to 8 times) in the synthesis of highly functionalized piperidines. Also, synthesis of 2-arylbenzimidazoles and 2-arylbenzothiazoles have been efficiently developed under mild condition from o-phenylenediamines or 2-aminothiophenol with aryl aldehydes via one-step process using catalytic amount (2.0 mol%) of nanocatalyst in air atmosphere as a green oxidant. The heterogeneous catalyst was characterized by scanning electron microscopy, atomic force microscopy, inductively coupled plasma spectrometry, thermogravimetry for analysis of nitrogen adsorption, and FT-IR spectroscopy.