Synthesis of Chiral Imidazole Amino Alcohols and Their Application in the Asymmetric Copper-Catalyzed Henry Reaction

Abstract

Using L-phenylalaninol as chiral precursor, a series of multi-aryl substituted imidazole amino alcohol derivatives containing appended chiral functionalities were synthesized through a "four component-one pot procedure" from the condensation reaction of L-phenylalaninol, dibenzoyl (benzil), ammonium acetate and different heterocyclic aryl-aldehyde. X-ray crystal analysis confirmed that the chiral carbon retained the S configuration of L-phenylalaninol. The chiral ligands in combination with Cu(OAc) 2 •H 2 O catalyzed the enantioselective Henry reaction of nitromethane and aromatic aldehydes with moderate to high yields and excellent enantioselectivities (＞99%) with S configuration. The easy availability of catalyst components, mild reaction conditions and high enantioselectivity make the system attractive for practical application.

Oil-Soluble Ultraviolet-Absorbing Carbon Dots Dispersed in Polyethylene Films as Antiaging Materials

“…Therefore, an aminoimidazole molecule was added to the original reaction system to make the amino group react with the carboxyl group of CA, and finally the imidazole ring was connected to the surface of the CDs. The imidazole ring contains a tertiary N atom with a lone pair of electrons, which can combine with protons in acidic conditions to make them positively charged. , Based on this, different types of surface ligands, especially AOT, were used to connect with the protonated N atom. Finally, AOT-CDs with long carbon chains on the surface were formed by surface modification of Im-CDs such that they could be uniformly dispersed in nonpolar solvents.…”

“…The imidazole ring contains a tertiary N atom with a lone pair of electrons, which can combine with protons in acidic conditions to make them positively charged. 52,53 Based on this, different types of surface ligands, especially AOT, were used to connect with the protonated N atom. Finally, AOT-CDs with long carbon chains on the surface were formed by surface modification of Im-CDs such that they could be uniformly dispersed in nonpolar solvents.…”