With alanine as a transient directing group, Pdcatalyzed regioselective alkynylation at the indole C4-position was successfully established in a good yield. The total synthesis of the PAF antagonist demonstrated the synthetic utility of this protocol. The regioselectivity was explicitly proven by the prepared C4selective palladacycle intermediate in the catalytic process and the DFT calculation of the energy barriers of C4-and C2-site-selective C−H activation of indole.