Rhodium(III)‐Catalyzed Alkynylation of 4‐Arylphthalazin‐1(2H)‐one Scaffolds via C‐H Bond Activation.

Selective C–H bond alkynylation toward modular access to material and pharmaceutical molecules is of great desire in modern organic synthesis. Disclosed herein is rhodium(III)‐catalyzed selective C–H bond mono‐/bialkynylation of 4‐aryl phthalazin‐1(2H)‐one was developed. The silver salt AgSbF6 are demonstrated to play a vital role in promoting the bialkynylation reactions. The present alkynylation strategy is simple, efficient, and features high functional group tolerance and broad substrate scope under an air atmosphere. Additionally, 6‐aryl pyridazin‐3(2H)‐one scaffold is amenable to the selective monoalkynylation and sequential bialkynylation, respectively. [ABSTRACT FROM AUTHOR]