Generation of diverse 1-(isoquinolin-1-yl)guanidines via a sequential multi-component/cross-coupling reaction

A multi-component reaction of 2-alkynylbenzaldehyde, 4-methylbenzenesulfonohydrazide, carbodiimide, and bromine is reported, which generates 1-(4-bromoisoquinolin-1-yl)guanidines in good yields under mild conditions. The products could be further elaborated via a palladium-catalyzed Suzuki–Miyaura coupling reaction, leading to the diverse 1-(isoquinolin-1-yl)guanidines.