Tandem Friedel-Crafts acylation and alkylation of arenes with 2-alkenoyl chlorides were investigated under the catalysis of Lewis acids. The cascade reaction affords dihydrochalcones in good yields accompanying 1-indanone derivatives in some cases, in the presence of anhydrous aluminum chloride. The scope. limitation, and mechanism of the tandem reaction were also explored. The intermolecular Friedel-Crafts alkylation for the formation of dihydrochalcones is more favorable than the intramolecular one for the generation of 1-indanones in the tandem reaction due to a stable six-membered ring transition state. The sequent process was further studied by the DFT computations at the M06-2X/6-31G(d) level, which are in great agreement with the experimental observation and support the proposed mechanism. The current method provides a convenient and economic method to synthesis of dihydrochalcones. (C) 2012 Elsevier B.V. All rights reserved.