Controlled photorelease of alkynoic acids and their decarboxylative deprotection for copper-catalyzed azide/alkyne cycloaddition.

A controlled photorelease of alkynoic acids from the meso-methyl BODIPY photoremovable protecting group facilitates their subsequent efficient decarboxylation to give terminal alkynes for a CuI-catalyzed azide/alkyne cycloaddition. The quantum efficiencies of the photochemical step and the kinetics of the click reaction step are reported.

Near-infrared fluorescent 9-phenylethynylpyronin analogues for bioimaging.

The syntheses and biological applications of two novel fluorescent 9-phenylethynylpyronin analogues containing either carbon or silicon at the position 10 are reported. Both fluorescent probes exhibited a relatively strong fluorescence in methanol and phosphate buffer saline in the near-infrared region (705-738 nm) upon irradiation of either of their absorption maxima in the blue and red regions. The compounds showed high selectivity toward mitochondria in myeloma cells in vivo and allowed their visualization in a favored tissue-transparent window, which makes them promising NIR fluorescent tags for applications in bioimaging.