A straightforward, regioselective, and step-economical ligand-free palladium-catalyzed decarboxylative functionalization of coumarin-3-carboxylic acids is devised. This protocol is compatible with a wide variety of electron-donating and -withdrawing substituents and allows for construction of various biologically important π-electron extended coumarins.

Nanodiamonds (NDs) represent an emerging class of nanomaterials that have been used for a variety of applications including biosensing and imaging, drug delivery, energy storage and conversion, and quantum sensing. Many of these application areas require precise control over their ND surface properties to maximize and/or enhance the interaction between the particles and their surrounding environment. In this contribution, we review recent advances in the surface functionalization techniques of NDs with an emphasis on the biological applications of the material.

Free radicals and oxidative stress play important roles in the deterioration of materials, and free radicals are important intermediates in many biological processes. The ability to detect these reactive species is a key step on the road to their understanding and ultimate control. This short review highlights recent progress in the development of reagents for the detection of free radicals and reactive oxygen species with broad application to materials science as well as biology.

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A novel regioselective a-arylation of coumarins with readily available arenesulfonyl chlorides and sodium arenesulfinates via palladium-catalyzed direct C À H functionalizations under mild reaction conditions is described. This protocol presents an unexpected and highly regio-controlled arylation of coumarins at C-3 to construct interesting 3-arylcoumarins with fascinating biological and fluorescent properties. The regioselectivity observed is in sharp contrast with that expected for the Heck reactions.

Two novel cell-permeable and bacteria-compatible 'turn-on' fluorescent probes, designed to be compatible in a multi-dye system and to fluoresce in the blue region exhibiting emission maxima of 440-490 nm, were synthesized. The profluorescent nitroxide probe (11) was developed to visualize and quantify free radical and redox processes, and the Cu(II)-complexed coumarin-based probe (16a) was developed for NO detection. Confocal laser-scanning microscopy and subsequent digital analysis of Pseudomonas aeruginosa biofilms stained with 11 or 16a determined that free radical and redox processes and NO generation occur predominantly in live cells during normal biofilm growth.

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A novel regioselective α‐arylation of coumarins with readily available arenesulfonyl chlorides via palladium‐catalyzed direct C—H functionalization under mild reaction conditions is described.