Combining Trifunctionalization\nof Alkynoic Acids,\nArene ortho C–H Functionalization and Amination: An Approach\nto Unsymmetrical 2,3-Diaryl Substituted Indoles

Here we report a simultaneous construction of two C–C\nand\ntwo C–N bonds in a unified procedure that incorporates alkynoic\nacid trifunctionalization, ortho C–H functionalization, and\namination cascade. In an ordered process, the regioselective alkyne\ninsertion reaction is favored over the decarboxylation process. The\npresence of the carboxyl group in alkynoic acid ensures the high regioselectivity\nin the carbopalladation process, paving the way for a novel method\nto synthesize unsymmetrically 2,3-diaryl substituted indole scaffolds\nwith excellent regioselectivity. The protocol is demonstrated to be\nsuitable for gram-scale synthesis.