Visible-Light Mediated, Photocatalyst-Free C−S Bond Formation via EDA Complex Formation

The presence of sulphur groups in the structures of many natural products and therapeutic candidates makes sulfur-containing molecules indispensable. In organic chemistry, the study of carbon-sulfur (C−S) bond formation via electron donor-acceptor (EDA) complexes is a dynamic and developing field. EDA complexes facilitate a variety of chemical transformations, including the production of C−S bonds, by interacting between an electron-rich donor and an electron-deficient acceptor. In this review, we focus on the literature reports on formation of electron donor-acceptor complex (EDA) between appropriate starting materials. Some new research investigates the use of light to stimulate C−S bond formation using EDA complexes. Photo-redox catalysis is a promising field in which substrates can be activated under gentler circumstances. In this review, we have highlighted the photoactivation of the EDA complex and an intermediate formed in the reaction itself. We classified the collection of the journal under the following headings such as one pot ring annulation and cyclization involving C−S bond formation, C−S bond formation by dehalogenation, C−S bond formation in multicomponent reaction, C−S bond formation by leaving group, C−S bond formation on alkene/alkyne and other miscellaneous.