In comparison to alkyl monoboron or 1,2-diboron, which can generate alkyl radicals via tetracoordinate boron species under photocatalytic conditions, the participation of gem-diborons as substrates in such reactions remains to be developed. Herein, we report a method utilizing gem-diborons as starting materials to generate α-boryl radicals, which then react with various olefins, successfully and efficiently constructing a diverse range of high-value homoallylic boronates; meanwhile, the gem-difluorohomoallylic skeletons could also be smoothly obtained. This transformation demonstrates broad substrate scope and excellent tolerance toward functional groups, enhancing the utility of gem-diboron as precursors for C-C bond construction and the production of valuable products.