摘要:
The present invention provides compounds having the formula A: (A) or pharmaceutically acceptable salt thereof, wherein W, R1, R2 and R5 are as defined in classes and subclasses herein, and pharmaceutical compositions thereof, as described generally and in subclasses herein, which compounds are useful as cytotoxic agents towards proliferating and/or quiescent cancer stem cells, and thus are useful, for example, for the treatment of cancer.