An efficient and greener method for the synthesis of styrylquinoxalin-2(1H)-ones has been developed using TAPSO as a catalyst. The reaction occurs smoothly at 120 °C under solvent free conditions and the desired products are obtained in good to excellent yields. The advantages offered by the method are operational simplicity, solvent free reaction conditions, shorter reaction times and high product yields.
Monitoring intracellular NAD(P)H is of great significance for evaluating cellular redox homeostasis and mitochondrial metabolic activity. Herein, we designed and synthesized a thiazolium-quinolinium hemicyanine fluorescent probe, T-EQ, for the sensitive detection of NAD(P)H and live-cell imaging. Upon reaction with NAD(P)H, T-EQ undergoes reduction of the quinolinium moiety, accompanied by a structural transformation from an A-π-A to a D-π-A system, thereby producing a fluorescence “Turn-on” response through an enhanced intramolecular charge transfer (ICT) process. Under physiological conditions, T-EQ exhibited a good linear fluorescence response toward NADH over the concentration range of 0–4 μmol L−1, with a detection limit of 0.020 μmol L−1. The probe also showed excellent selectivity over common ions and biologically relevant species, and reached response equilibrium within 15 min. Moreover, T-EQ displayed low cytotoxicity in MCF-7 cells and was successfully applied to fluorescence imaging of NADH-associated status. These results demonstrate that T-EQ is a promising fluorescent tool for monitoring NAD(P)H-associated redox and metabolic processes in living cells.
An efficient and practical protocol for the construction of functionalized gem-difluorohomoallylic boronates through a base-promoted defluoroalkylborylation of α-trifluoromethyl alkenes and gem-diborylalkanes has been developed. This protocol features excellent functional group compatibility, scalability, diverse derivatizations of the boron moiety, and late-stage modification of bioactive molecules. Preliminary mechanistic investigations are consistent with an ionic SN2′ pathway.
We report a selective demethylation of 2-O-methyl group of 1,2,3-trimethoxybenzene derivatives with DIBAL-H. More than 2.0 equivalent of DIBAL-H is required for the reaction to proceed the reaction completely. The presence of adjacent methoxy groups to the demethylated methoxy group is essential for the reaction. Finally, a plausible mechanism for this reaction is proposed.
