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The isocyanide insertion into sulfanyl-phthalides under Lewis acid conditions is reported with full details. This sequential three-component reaction affords a new straightforward and highly convenient method for the preparation of 3-amino-4-sulfanyl isocoumarins, the potential of which is still unexplored. [ABSTRACT FROM AUTHOR]

In this work, Fluorescent False Neurotransmitter 102 (FFN102), a synthesized analogue of biogenic neurotransmitters, was demonstrated to show both pH-dependent fluorescence and electroactivity. To study secretory behaviors at the single-vesicle level, FFN102 was employed as a new fluorescent/electroactive dual probe in a coupled technique (amperometry and total internal reflection fluorescence microscopy (TIRFM)). We used N13 cells, a stable clone of BON cells, to specifically accumulate FFN102 into their secretory vesicles, and then optical and electrochemical measurements of vesicular exocytosis were experimentally achieved by using indium tin oxide (ITO) transparent electrodes. Upon stimulation, FFN102 started to diffuse out from the acidic intravesicular microenvironment to the neutral extracellular space, leading to fluorescent emissions and to the electrochemical oxidation signals that were simultaneously collected from the ITO electrode surface. The correlation of fluorescence and amperometric signals resulting from the FFN102 probe allows real-time monitoring of single exocytotic events with both high spatial and temporal resolution. This work opens new possibilities in the investigation of exocytotic mechanisms., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The small and synthetically easily accessible coumarinylmethyl backbone has been modified to generate a family of photolabile protecting groups with redshifted absorption. We relied on introducing electron-donating groups in the 7 position and electron-withdrawing groups in the 2-, and 2- and 3 positions. In particular, we showed that the diethylamino-thiocoumarylmethyl and the diethylamino-coumarylidenemalononitrilemethyl are relevant for uncaging with cyan light. They both exhibit a significant action cross section for uncaging in the 470-500 nm wavelength range and a low light absorption between 350 and 400 nm. These attractive features are favorable to perform chromatic orthogonal photoactivation with UV and blue-cyan light sources, respectively., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

This paper evaluates the 2-hydroxyazobenzene platform for tailoring proton concentration pulses and oscillations with monochromatic light. The easily prepared 2-hydroxyazobenzenes exhibit large absorptions in the near-UV range. Photoisomerization was investigated by UV/Vis absorption, (1)H NMR spectroscopy, and steady-state fluorescence emission. In the whole investigated series, the trans stereoisomer of the 2-hydroxyazobenzene motif provides the corresponding cis derivative with an action cross section in the 10(3) M(-1) cm(-1) range. At the same time, photoisomerization is accompanied by a significant pK drop of the phenol group. According to the phenyl-substituent pattern, cis-to-trans thermal back-isomerization can be tuned in the 10 ms-100 s range. Up to 2 units of reversible pH drops or pH oscillations on the 10 s timescale have been obtained by appropriately tailoring single-wavelength illumination of 2-hydroxyazobenzene solutions.