Natural α-Amino Acids Applied in the Synthesis of Imidazo[1,5-a]N-heterocycles under Mild Conditions
摘要:
A facile iodine-mediated decarboxylative cyclization from alpha-amino acids and N-heterocyclic carbaldehydes was developed. By virtue of this method, a series of imidazo[1,5-a]N-heterocycles can be synthesized efficiently under mild conditions. A tentative reaction mechanism was proposed based on the experimental results and previous reports.
A copper(I)-catalyzed direct transannulation of N-heteroaryl aldehydes or ketones with alkylamines via C-sp(3)-H amination has been achieved using molecular oxygen as a sole oxidant. N-Heteroarenes are employed as the amine source. This transformation provides a rapid and concise access to multifunctional imidazo[1,5-a]pyridines.