The invention is directed to a compound represented by the following structural formula and pharmaceutically acceptable salts thereof:Compounds represented by this structural formula are kinase inhibitors and are therefore disclosed herein for the treatment of cancer. Definitions for the variables in the structural formula are provided herein.本發明係關於以下結構式所表示之化合物及其醫藥學上可接受之鹽:此結構式所表示之化合物為激酶抑制劑且因此在本文中揭示用於治療癌症。結構式中變數之定義提供於本文中。