Suzuki Cross‐Coupling Reaction with Genetically Encoded Fluorosulfates for Fluorogenic Protein Labeling.

A palladium‐catalyzed cross‐coupling reaction with aryl halide functionalities has recently emerged as a valuable tool for protein modification. Herein, a new fluorogenic modification methodology for proteins, with genetically encoded fluorosulfate‐l‐tyrosine, which exhibits high efficiency and biocompatibility in bacterial cells as well as in aqueous medium, is described. Furthermore, the cross‐coupling of 4‐cyanophenylboronic acid on green fluorescent protein was shown to possess a unique fluorogenic property, which could open up the possibility of a responsive "off/on" switch with great potential to enable spectroscopic imaging of proteins with minimal background noise. Taken together, a convenient and efficient catalytic system has been developed that may provide broad utilities in protein visualization and live‐cell imaging. [ABSTRACT FROM AUTHOR]