Chemoselective Synthesis of Lenalidomide-Based PROTAC Library Using Alkylation Reaction.

An organic base-promoted chemoselective alkylation of lenalidomide with different halides was developed, which offers a novel approach to a highly functionalized lenalidomide-based PROTAC library under mild reaction conditions. DIPEA was found to act as an efficient base to trigger facile generation of arylamine alkylation products compared with inorganic bases. This library was successfully applied to BET PROTAC, which not only degraded BET protein but also effectively inhibited cancer cell proliferation.