Solvent- and catalyst-free aza-Michael addition of imidazoles and related heterocycles

Abstract

This work demonstrates the scope and limitations of the aza-Michael addition of imidazoles and related heterocycles with electron deficient olefins under solvent-and catalyst-free conditions. The reaction proceeds at 80°C within hours towards completion as long as the azole derivative is sufficiently soluble [a] K.

Michael Acceptors Tuned by the Pivotal Aromaticity of Histidine to Block COVID-19 Activity

“…Actually, the facility of obtaining a proton by this ring is extremely helpful for the thiol group of Cys145 to deprotonate. This protonated imidazole together with any water molecule around then can create an oxyanion activating the keto group of 13b , 14 , 15 where the positive charge on the carbon aims for the negative charge on the deprotonated sulfur, facilitating C–S bond formation.…”

Solvent-dependent activity of Candida antarctica lipase B and its correlation with a regioselective mono aza-Michael addition - experimental and molecular dynamics simulation studies

“…The possibility of undergoing an aza-Michael addition without using any catalyst or solvent was reported for amines previously ( Kodolitsch et al., 2020 ; Ranu et al., 2002 ). Noteworthy is failure of the reaction to generate the desired product with other solvents, including DCM and THF, which was in line with efficiency and activity of CALB in HEX as the nonpolar solvent compared with polar-solvents reported in literature ( Dutta Banik et al., 2016 ).…”