Despite the widespread usage of pre-formed copper-ligand complexes for promoting these transformations, the utilization of in-situ generated copper complexes remained relatively rare, despite their potential advantages. In 2018, the Peters and Fu research groups reported an advancement involving the application of an in-situ generated Cu(I)-BINAP-based photocatalyst in facilitating the di-functionalization of olefins with alkyl halides and anionic nucleophiles under blue light irradiation (Figure ). While a wide range of functional groups such as (pseudo)halides, epoxides, ketones, aldehydes, and alcohols were tolerated, 102 heteroarenes like indole and secondary amines were incompatible and resulted in deleterious side reactions (Figure ). The authors successfully synthesized a dimeric Cu(I) complex, [(BINAP)Cu(SCF3)]2 (10.5), exhibiting tailing absorption intensity in the blue-light region (380-520 nm). This complex also demonstrated notable photocatalytic activity, affording 81% yield of the alkyl-thioether product, indicative of its in-situ formation during the course of reaction. The mechanism involves oxidative quenching of the excited state of the in-situ generated Cu(I)-nucleophile complex (10.7) by the electrophilic alkyl-halides, followed by the addition of the resulting alkyl radicals to alkenes and subsequent cross-coupling with the Cu(II)-nucleophile complex (10.8), forming the desired product (Figure ).