The invention provides novel compounds having the general formula (I)(I) wherein R1, R2, Y, X, W, m and n are as defined herein, compositions including the compounds and methods of using the compounds.本發明提供具有通式(I)之新穎化合物、包括該等化合物之組合物及使用該等化合物之方法:(I) 其中R1、R2、Y、X、W、m及n如本文所定義。