A theoretical investigation on palladium-catalyzed one-pot coupling of aryl iodides, alkynes, and amines through CN bond cleavage for the synthesis of indole derivatives

Abstract

Detailed mechanism of one-pot coupling of aryl iodides, alkynes, and amines catalyzed by a palladium complexes is studied using density functional theory. The reaction of threecomponent proceeds in four steps after the insertion of alkyne into CAI bond. The four-component case comprises eight steps incorporating two times of nucleophilic addition. The CAN bond cleavage is rate-limiting. The reaction sequence is maintained the same. The function of metal Pd is reflected by the coordination ability and electrophility of different oxidation state. The high selectivity of ligand is originated from the style of electron distribution in CAN bond cleavage and amination steps. We also discuss the amination from a bonding orbital matching perspective by means of frontier molecular orbital analysis.