Catalyst Controlled Divergent C4/C8 Site-Selective C–H Arylation of Isoquinolones

Abstract

The catalyst-controlled C4/C8 site-selective C–H arylation of isoquinolones using aryliodonium salts as the coupling partners was developed. The C4-selective arylation was successfully achieved via an electrophilic palladation pathway. A completely different selectivity pattern was observed using an Ir­(III) catalytic system, which resulted in C–C bond formation exclusively at the C8 position. The isoquinolone scaffold can be conveniently equipped with various aryl substituents at either the C4 or C8 position