A metal-free sulfur neighboring group participation C-3 alkylation method between β-sulfur-α-alcohol and indole is documented. Due to its considerable generality and excellent selectivity, this method has been provided a facile access to synthetically useful α-indole-β-functions. Meanwhile, unlike traditional Friedel-Crafts and Mitsunobu reactions, the unique chemoselectivity and regioselectivity may be attributed to a synergetic mechanism with simultaneous C-O cleavage, C-S migration, and C-C formation occurring in the developed reaction.