Ultrasound-promoted regioselective synthesis of chalcogeno-indolizines by a stepwise 1,3-dipolar cycloaddition.

•New organochalcogen derivatives of indolizines were synthesized under US irradiation.•Novel examples of selanyl and tellanyl alkynes were prepared.•First derivatives of teluro-indolizine described in literature.•Photophysical study showed the influence of a chalcogen atom on the optical behavior.