Institute of General and Ecological Chemistry, Faculty of Chemistry, Lodz University of Technology, Żeromskiego 116, 90-924 Łódź, Poland, e-mail: anna.albrecht@p.lodz.pl ABSTRACT: Herein, we report a stereoretentive and decarboxylative C-3 functionalization of chromone-3-carboxylic acids with optically active aziridines via visible light irradiation. This metal-free and operationally simple protocol utilizes a simple combination of stable and inexpensive tetrabutylammonium iodide and visible light irradiation. It enables a facile and direct access to chiral 3-substituted chromenones with maintaining the optical purity of starting aziridines.Cross-coupling reactions allowing for efficient carbon-carbon as well as carbon-heteroatom bond formations are of crucial importance in the modern organic chemistry. 1 Among them transition-metal-catalyzed decarboxylative cross-couplings utilizing carboxylic acids as substrates occupy a prominent position. They offer several distinctive advantages related to availability and price of carboxylic acid derivatives, their stability and handling as well as generation of less-toxic carbon dioxide as the by-product that reduces the waste treatment costs. While these methods have proven particularly useful for C(sp 2 )-C(sp 2 ) bond formations and were applied for the synthesis of numerous relevant products ranging from pharmaceuticals to organic materials, their application in the C(sp 2 )-C(sp 3 ) remains limited. Consequently, there is a need for the development of alternative, transition-metal-free crosscoupling reactions allowing for C(sp 2 )-C(sp 3 ) bond formations.