N-Arylation of Amidines and Guanidines: An Update

Amidines and guanidines are prominent privileged motifs present in many biologically active synthetic compounds as well as natural products. Introduction of an aryl or heteroaryl group at a nitrogen atom of amidines and guanidines attenuates the basic properties of these cores, allows for appending various lipophilic groups and has, in turn, given rise to many new compounds endowed with diverse biological activities. This clearly validates N-aryl amidines and guanidines as an emerging privileged structure. The present review provides an update on the recent (2011-2015) developments in N-arylation chemistry, with a particular emphasis on the examples involving compounds with biological activity.