Visible-Light-Driven Iron-Catalyzed Atom Transfer Radical Addition of CH2Br2 to Alkenes: Facile Access to 1,3-Dibromo Compounds.

An efficient visible-light-mediated iron-catalyzed atom transfer radical addition (ATRA) reaction between CH2Br2 and various alkenes has been developed. This transformation provides direct access to synthetically valuable 1,3-dibromo compounds with excellent atom economy under mild reaction conditions. The protocol demonstrates remarkable versatility, exhibiting broad substrate scope and excellent functional group compatibility. Notably, the obtained 1,3-dibromo products function as highly versatile synthetic building blocks. Through rationally designed one-pot multistep transformations, these intermediates can be conveniently converted into structurally diverse derivatives, including oxetanes and allyl bromides, directly from terminal alkenes.