Control experiments revealed that light and TBAI were crucial for this transformation (Table 1, entries 14,15). While the reaction in the dark provided 3a in very low yield, no product 3a formation was identified in the absence of TBAI (Table , entries 14 and 15). Having accomplished the optimization studies, the goal of establishing scope and limitation of the methodology was pursued (Schemes 2 and 3). In the first part of scope studies various chromone-3-carboxylic acids 1a-k were reacted with (R)-2-phenyl-1-tosylaziridine 2a under optimized conditions (Scheme 2). To our delight, the target products 3a-k were obtained in high yields when electron-donating substituents were present on the aromatic ring in 3b-e. In the course of further studies it was found that when electron-withdrawing groups were introduced on the aromatic ring in chromone-3-carboxylic acids 1f-g,k the yield of the reaction was lower. It is worth to note that the developed methodology was efficient for disubstituted carboxylic acids 1i-k. Notably, reactions proceeded with the high degree of preservation of optical purity of 2a in most of the cases. Deterioration of stereospecificity of the process was observed when substituents were present in the 5 or 6 position of the chromone ring system (Scheme 3, compounds 3d,l,j,k) presumably for steric reasons. In the second part of scope studies different aziridines 2 were employed (Scheme 3). It was found that (R)-2-methyl-1-mesylaziridine participated in the reaction providing target product 3l with diminished and with excellent stereoselectivity. Subsequently, the influence of the protecting group at the nitrogen atom in 2 was evaluated. While mesylprotected aziridine 2c reacted smoothly, no product formation was observed for both Boc-protected 2d and unprotected aziridine 2e developed protocol proved to be unsuccessful and desired products were not present in the reaction mixture. Notably, all performed reaction afforded highly enantiomerically enriched products 3a-m confirming that optical purity of the aziridines 2 was maintained during the processes.