1. Initial Filtering: Filter the raw ChEMBL data to keep 'drug-like' compounds only (see Supporting Information for details). Lenient filtering criteria was applied such that the training data is effective for PROTACs applications where the warheads can be larger in size compared to traditional 'fragments'. 2. Reaction-based Slicing: Slice the filtered ChEMBL compounds following the protocol from our Lib-INVENT work using reaction SMIRKS. The result is a dataset of tuples with the structure: