A new class of α,β-unsaturated S-(1,3-benzoxazol-2-yl) thioesters of type 2 have been synthesized and effectively employed as electrophiles in the stereoselective alkylation of indoles. The combination of electronic as well as steric properties of such Michael acceptors allowed us to carry out FriedelCrafts alkylations of various substituted indoles in the presence of a catalytic amount (20 mol-%)