A series of trans- or cis-stilbenes have been synthesized in good to excellent yields via a functional group-dependent decarboxylation process from the corresponding 2,3-diaryl acrylic acids in a neutral CuI/1,10-phen/PEG-400 system under microwave conditions. The in situ generation of the recyclable catalytic complex, the use of environmentally benign solvent PEG-400, the operational simplicity, the short reaction times, as well as the functional group-dependent chemo- and stereo-selectivity have made the decarboxylation process a highly efficient and applicable protocol.

A novel bicoumarin-based fluorescent and colorimetric probe 7,7′-(acetoxy)-3,3′-(p-phenylene)bis(coumarin) (apbis-c) for the highly sensitive detection of amines/ammonia in solution and ammonia vapor in air was constructed for the first time by using the Perkin reaction between 1,4-phenylenediacetic acid and 2,4-dihydroxybenzaldehyde. Instant color changes and real-time fluorescence responses were observed for apbis-c after treatment with different primary and secondary aliphatic amines as well as ammonia in THF/DMSO. Paper-based sensors were prepared by simply depositing apbis-c on filter paper and used in the highly selective and sensitive detection of ammonia vapor in air with an experimental detection limit of 6.85 ppm (the calculated LOD is 0.71 ppm). A plausible mechanism for the fluorescence and colorimetric responses of apbis-c to ammonia was proposed based on ¹H NMR study and DFT calculations. In addition, practical studies revealed that apbis-c could be used for the preparation of fluorescent invisible ink, food spoilage indicators and naked eye sensors for lysine/arginine.

The substitutional effect in the selective synthesis of cis, trans stilbenes and 3-arylcoumarins has been described. The regio- and geometrical selectivity for synthesis of stilbene derivatives under the Perkin strategy strongly depends on the presence or absence of hydroxyl group as well as their positions in the phenyl ring. As a result, practical synthetic strategies were established for preparing various natural stilbenes including combretastatin A-4, pterostilbene, and resveratrol with satisfactory yields (49.2–63.7%).

A copper-catalyzed intramolecular cross dehydrogenative C–O coupling reaction of 2′-hydroxyl-3-arylcoumarins was developed.