Impact of Functional Groups on the Copper-Initiated N-Arylation of 5-Functionalized Pyrrolidin-2-ones and Their Vinylogues

The electronic effects governing the N-arylation of pyrrolidone were investigated. The generalization of our preliminary findings on a copper(I)-catalyzed Csp²-N coupling process was first improved with a wide variety of aryl and heteroaryl halides and methyl pyroglutamate. The optimized protocol was further extended to pyrrolidin-2-ones substituted at the C5-position with an aryl group bearing an electron-donating or electron-withdrawing group as well as to some of their substituted enaminoester vinylogues. The impact of substituents at the N- and C5-position on these coupling processes seemed to be pivotal for determining both the reaction profiles and yields.