Photoinduced, copper-catalyzed coupling reactions are emerging as a powerful method for generating Csp3–Y (Y = C or heteroatom) bonds from alkyl electrophiles and nucleophiles. Corresponding three-component couplings of alkyl electrophiles, olefins, and nucleophiles have the potential to generate an additional Csp3–Y bond and to efficiently add functional groups to both carbons of an olefin, which serves as a readily available linchpin. In this report, we establish that a variety of electrophiles and a trifluoromethylthiolate nucleophile can add across an array of olefins (including styrenes and electron-poor olefins) in the presence of CuI/binap and blue-LED irradiation, thereby generating trifluoromethyl thioethers in good yield. The process tolerates a wide range of functional groups, and an initial survey of other nucleophiles (i.e., bromide, cyanide, and azide) suggests that this three-component coupling strategy is versatile. Mechanistic studies are consistent with a photoexcited Cu(I)/binap/SCF3 complex serving as a reductant to generate an alkyl radical from the electrophile, which likely reacts in turn with the olefin and a Cu(II)/SCF3 complex to afford the coupling product.

Substrates in excited state differ significantly from the corresponding ground state so that they are treated as different chemical species with diverse physical properties and chemical reactivity. Therefore, applying photocatalytic systems to activate substrates becomes increasingly popular. Although photosensitizers serve as the core of the photocatalytic reaction, the design of a photosensitizer has not been taken for granted. By modifying ligands of organometallic complexes to optimize properties of photosensitizers, we successfully achieved a series of iridium complexes with long excited triplet-state lifetime, high triplet excited-state energy, strong absorption, and robust stability. The efficacies of the prepared iridium complexes as photosensitizers were evaluated toward various challenging photocycloaddition reactions (e.g., thia-Paternò–Büchi reaction and multicomponent one-pot aza-photocyclization) between heterocyclic compound maleimides and unsaturated moieties that are not efficient to complete with well-established photosensitizers.

all the tissue expanders expanded to their maximum size (2.8 times) and were a reliable product for creating a space between soft tissue and bone. The overlying soft tissue remained in excellent shape. There was no difference in the soft tissue volume and the bone volume between the tunnel and the flap approach after 40 days.

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