Compounds having activity as chemotherapeutic agents are provided. The compounds have the following structure (I): or a pharmaceutically acceptable salt, stereoisomer, isotopic form or prodrug thereof, wherein R1a, R1b, R1c, R1d, L, and are as defined herein. Methods associated with preparation and use of such compounds, pharmaceutical compositions comprising such compounds and methods for treating cancer (e.g., hematological cancers) are also provided.