Amide directed selectivity switch in distal C-H arylation of α-naphthoic acids

Abstract

Remote C4-H functionalization of a-naphthoic acids is highly challenging due to the presence of proximally more accessible C-H bonds at the C2 and C8 positions. Herein, we report the first palladium-catalysed direct C4 arylation of 1-naphthamides with high regioselectivity and excellent functional group compatibility. The regioselectivity of this one-step reaction could be switched to the C7 position by simply changing the directing group under otherwise identical conditions. Diverse aryl couples were found compatible for both C4 and C7 arylation. Control experiments and kinetic studies were carried out to identify the mechanistic motives of the unique selectivity switch.