Parisa Zamani

A practical and efficient synthetic procedure to novel chromeno[3,2-d]oxazoles through a one-pot sequential multistep process is presented. This procedure proceeds efficiently in propylene carbonate (PC) as a green solvent and affords a wide range of the chromenooxazole scaffolds.

Herein, we introduce a reusable catalyst consisting of a deep eutectic solvent made up of choline chloride and p‐toluene sulfonic acid (pTSA) covalently immobilized on magnetic nanoparticles (MNPs) as an agent for chemoselective direct ipso etherification and amination of naphthols. The bonding of the DES to the surface of the nanoparticles has increased the catalytic activity of the DES and also has simplified catalyst recovery from the reaction mixture. The MNP bound DES particles with an average size of 12±2 nm was characterized by FTIR, PXRD, HRTM, TGA, and VSM. For 16 tested etherification reactions, the functionalized magnetite nanoparticle catalyst gave an average yield of 84%; for 5 tested aminations the average yield was 77%. For all 23 tested reactions the yield was above 70% and pTSA Brønsted acid loading was only 0.45 mol%. The catalytic performance could be attributed to the dispersion of the nanoparticles, strong DES‐support interactions and interactions of the hydrogen donor species with naphthols. This work is the first catalytic examination of PDES covalently bonded on MNPs as a platform for organic transformations. magnified image

A combination of natural deep eutectic solvents with microfluidic technology presents a powerful and attractive technique in the modern synthesis of fine chemicals.

Convenient procedures using the title catalyst are presented for the conversion of various alcohols.