Synergistic photoredox and copper catalysis by diode-like coordination polymer with twisted and polar copper–dye conjugation

Abstract

Synergistic photoredox and copper catalysis confers new synthetic possibilities in the pharmaceutical field, but is seriously affected by the consumptive fluorescence quenching of Cu(II). By decorating bulky auxiliaries into a photoreductive triphenylamine-based ligand to twist the conjugation between the triphenylamine-based ligand and the polar Cu(II)–carboxylate node in the coordination polymer, we report a heterogeneous approach to directly confront this inherent problem. The twisted and polar Cu(II)–dye conjunction endows the coordination polymer with diode-like photoelectronic behaviours, which hampers the inter- and intramolecular photoinduced electron transfer from the triphenylamine-moiety to the Cu(II) site and permits reversed-directional ground-state electronic conductivity, rectifying the productive loop circuit for synergising photoredox and copper catalysis in pharmaceutically valuable decarboxylative C(sp3)–heteroatom couplings. The well-retained Cu(II) sites during photoirradiation exhibit unique inner-spheric modulation effects, which endow the couplings with adaptability to different types of nucleophiles and radical precursors under concise reaction conditions, and distinguish the multi-olefinic moieties of biointeresting steride derivatives in their late-stage trifluoromethylation-chloration difunctionalisation.

Incorporating Photochromic Triphenylamine into a Zirconium–Organic Framework for Highly Effective Photocatalytic Aerobic Oxidation of Sulfides

“…Therefore, ZrOCl 2 ·8H 2 O was selected as the metal source for the MOF construction. A simple triphenylamine-containing tricarboxylate ligand, that is, 4′,4‴,4‴″-nitrilotris-(([1,1′-biphenyl]-4-carboxylic acid)) (H 3 NBC), was then prepared as the organic building unit in the construction of targeted photoactive MOF, and yellow powder was obtained after the solvothermal reaction in N , N ′-dimethylformamide (DMF).…”

Cuprous Cluster-Based Coordination Sheets as Photocatalytic Regulators to Activate Oxygen, Benzoquinone, and Thianthrenium Salts

“…The redox potential of excited-state Cu– TFT + /Cu– TFT * was calculated to be −2.28 V on the basis of a free energy change of 2.02 eV (Figure S13). , This potential was more negative than that of benzoquinone (denoted BQ ; E 1/2 ( BQ / BQ •– ) = −0.35 V vs Ag/AgCl; Figure S14). As a consequence, Cu– TFT was considered to be a candidate for the photocatalysis of the oxidative coupling of terminal alkynes to form ketones coupled with benzoquinone.…”

Chemo- and regioselective benzylic C(sp3)–H oxidation bridging the gap between hetero- and homogeneous copper catalysis

“…Fascinatingly, hazardous peroxide has been replaced with molecular oxygen merging copper powder catalyst with organic photocatalyst, rose bengal. Though there are some reports for copper salt/photoredox ( Barzanò et al., 2020 ; Shi et al., 2020 ; Tao et al., 2017 ; Zheng et al., 2020 ) or copper/O 2 systems ( Liang et al., 2019 ), to the best of our knowledge, this is the first report for bulk metallic copper/photocatalysis to couple with O 2 in benzylic C‒H oxidation. Remarkably, a highly reactive, substrate-dependent soluble catalyst is formed from the copper powder during the reaction to achieve high degree of chemoselective sp 3 vs sp 2 C‒H oxidation ( Scheme 1 D).…”