KI-mediated three-component annelation for the regioselective synthesis of angular azolo[1,5-a]pyrimidine derivatives

Herein, a straightforward and regioselective avenue to angular azolo[1,5-a]pyrimidine derivatives via the three-component cyclization of aldehydes and alpha-aminoazoles with cycloketones is presented. The initiation of the condensation reaction between aldehydes and amines is key to the achievement of high regioselectivity in this process through bypassing the general aldol condensation of aldehydes and ketones. It is worth noting that this simple and scalable protocol was successfully applied to the derivatization of several structurally diverse natural products and pharmaceuticals.