•A turn-on fluorescent probe ACR for selective detection of H2O2 was constructed based on a new reaction site and a non-oxidative mechanism.•Experiments designed for deep exploration of the detection mechanism showed that probe ACR was made up of three essential parts, chlorine atom, azide group and an active carbonyl.•Probe ACR showed high selectivity and sensitivity for H2O2 even in the presence of micromole which was proved by preliminary fluorescence imaging experiments in cells.A turn-on fluorescent probe ACR {6′-[2-(azidomethyl)benzoyl]-7′-chloro-N,N-diethylrhodol} for selective detection of H2O2 was developed. An ester bond was broken by the nucleophilic substitution of H2O2 which released strong fluorescence. Probe ACR was proved to be made up of three essential parts, chlorine atom, azide group and an active carbonyl. This probe showed high selectivity for H2O2 and a linear fluorescence intensity enhancement with a wide range of concentrations of H2O2. Fluorescence imaging experiments in HeLa cells indicated its potential to image H2O2 in biological systems.Download high-res image (135KB)Download full-size image

An efficiently scalable synthesis of key intermediate toward mirabegron has been developed via a mixed anhydride method, employing PivCl instead of EDCI and HOBt. The developed process produced (R)-2-hydroxy-N-(4-nitrophenethyl)-2-phenylacetamide (10) in 91.5–92.3% yield and >99.0% HPLC purity under mild conditions. During this process, a side reaction induced by triethylamine hydrochloride was discovered and investigated, which was ultimately avoided by executing the reaction in a biphasic solvent system.Keywords: intermediate; mirabegron; mixed anhydride method; PivCl;

A turn-on probe (ANR) for fast detection of H2S is constructed based on a 2-(azidomethyl)-4-nitrobenzoate moiety as a trap group. This group is very effective for the design of H2S probes especially with electron rich dyes. The potential biological applications of ANR were proved by employing it for fluorescence imaging of H2S in living cells.