Synthesis and photophysical properties of functionalized fluorescent 4 H -chromenes and benzo[a]chromenophenazines as Fe 3+ and Cu 2+ ion sensor

•Synthesis of fluorescent 4H-chromenes and benzo[a]chromenophenazines via MCR is reported.•A reusable Amberlite resin has been used as catalyst.•Evaluation of photophysical properties revealed that these are blue emissive fluorescent materials.•Both 4H-chromene 5a and benzo[a]chromenophenazine 6a have been found to be Fe3+ and Cu2+ metal ion sensors.