The present invention provides compounds of FormulaI', or pharmaceutically acceptable salts thereof, pharmaceutical compositions thereof, and methods of use thereof for treating cellular proliferative disorders (e.g., cancer).本發明提供式I'化合物或其醫藥學上可接受之鹽、其醫藥組合物及其用於治療細胞增殖性病症(例如,癌症)之使用方法。