The cycloaddition of aziridines with isothiocyanates, isoselenocyanates and carbon disulfide is described using pyrrolidine on water. This protocol affords a potential route for the construction of the five membered heterocycles with high yields.

Sustainable assembly of imidazolidines is accomplished via a sequential stereospecific ring opening and C–H amination using aziridines with secondary cyclic amines under visible light mediated indazoloquinoline photoredox catalysis at ambient conditions. Optically active aziridines are coupled with high enantiomeric purities. The computational studies provide insights on the redox properties of the catalysts as well as a profile of the reaction.

Metal‐free regioselective [3+2]‐cycloaddition of 2‐aryl/alkylthiiranes with isothiocyanates, isoselenocyanates and carbodiimides is developed using BF2OTf⋅OEt2 to produce 2‐imino‐dithiolane/‐thiaselenolane/‐thiazolidine frameworks at room temperature. The selectivity, substrate scope and scale up are the important practical features.

A domino Bi‐catalysed C−N/C−S bond formation of N‐sulfonylaziridines is developed with 1,4‐dithiane‐2,5‐diol to give 3,4‐dihydro‐1,4‐thiazines at room temperature. The use of Bi(OTf)3 as a catalyst, atom economy and regioselectivity are the important practical features.magnified image

Thiazolidine and selenazolidine derivatives such as (III), (V), (VII), and (IX) are simply and efficiently synthesized via [3 + 2] cycloaddition reactions under mild conditions under air.