STEFs: Activated Vinylogous Protein-Reactive Electrophiles.

Reported here is the synthesis of a class of semi-oxamide vinylogous thioesters, designated STEFs, and the use of these agents as new electrophilic warheads. This work includes preparation of simple probes that contain this reactive motif as well as its installation on a more complex kinase inhibitor scaffold. A key aspect of STEFs is their reactivity towards both thiol and amine groups.