Rhodium-Catalyzed C-H Functionalization of N-(2-Pyrimidyl) indole with Internal Alkynes: Formation of Unexpected Products by Regulating the Amount of Silver Acetate

Herein we disclose an uncommon Rhodium(III)-catalyzed C2-selective functionalization of N-(2-Pyrimidyl)indole with internal alkynes. Excess amounts of silver acetate (5.0 equiv.) were found to be crucial for the efficient C2 naphthylation and C2 enol esterification of indoles. In sharp contrast, 2.0 equivalents of silver acetate resulted in the C-H alkenylation only. Control experiments were also carried out to briefly study the mechanism of this transformation.