In conclusion, we report the efficient one-pot synthesis of a series of BCB-sulfoximines and diversification with the intact 3-D warhead structure. The modification of the N-substituent provided tuneable strain-release reactivity across a broad reactivity range, which will allow the reactivity to be tailored to applications. BCBbridgehead functionalization and aryl cross-coupling reactions will allow rapid diversification and fragment growth, and also facilitate their incorporation into screening collections. BCB sulfoximines demonstrated selective strain-release reactivity towards cysteine nucleophiles under biocompatible conditions. N-Acyl, N-sulfonyl and N-carbamoyl sulfoximine BCBs possess reactivity sufficient for a range of potential uses. We demonstrate the potential for enantioselective labelling in cell lysates. We anticipate these reagents will add another opportunity to screen warheads in an electrophile first strategy, and for screening of enantiopair probes. Tuning to lower reactivity may find application in targeted inhibitors. Further studies to exploit these reactivity profiles are underway in our labs.