Cu^I-catalyzed hetarylation of natural di- and polyamines with halopyridines

Copper(i)-catalyzed hetarylation of natural diamines (putrescine, cadaverine, and hexane-1,6-diamine), their analogs (propane-1,3-diamine and decane-1,10-diamine), as well as natural tri- (spermidine) and tetraamines (spermine) with 2-bromo, 2-iodo-, and 3-iodopyridines was studied. The CuI—2-isobutyrylcyclohexanone (10—20 mol.%) catalytic system provides the best results in the synthesis of target N,N´-dipyridinyl diamine derivatives. In some cases, an increase in the catalyst loading leads to an increase in the yields of the dihetarylated compounds. In the case of tri- and tetraamines, this catalytic system favors the predominant hetarylation of the primary amino groups with 2-bromopyridine and 3-iodopyridine.