Benzylic Trifluoromethyl Accelerates 1,6-Elimination Toward Rapid Probe Activation.

Activity-based detection of hydrogen sulfide in live cells can expand our understanding of its reactivity and complex physiological effects. We have discovered a highly efficient method for fluorescent probe activation, which is driven by HS-triggered 1,6-elimination of an α-CF-benzyl to release resorufin. In detecting intracellular HS, 4-azido-(α-CF)-benzyl resorufin offers significantly faster signal generation and improved sensitivity compared to 4-azidobenzyl resorufin.