A Lewis acid-promoted DÀ A cyclopropane reacting with 1,1diarylethylenes was developed. This reaction features mild reaction conditions, easy availability of starting materials, good functional group tolerance and high yields (up to 91%).Moreover, substituent effects on product distribution were observed. The scenario of the reaction pathway was supposed to involve the Sc(OTf) 3 -mediated ring-opening 1,3-dipole intermediate followed by the attack of 1,1-diarylethylenes.available donor-acceptor cyclopropanes as versatile reagents. Efforts to develop conditions for the enantioselective reactions of donor-acceptor cyclopropanes, are currently underway. The robustness and practicality of the current method will be further demonstrated by other applications.