Boosting Photocatalytic Activity in Cross‐Coupling Reactions by Constructing Pd‐Oxide Heterostructures

Abstract

The design of heterogeneous photocatalysts for organic synthesis has attracted great attention for achieving enhanced catalytic performance under light illumination. However, the effects of photocatalytic processes on organic reactions are quite complicated. In this work, we construct a series of Pd‐oxide heterostructures and then evaluate their catalytic performances on cross‐coupling reactions. The investigation results reveal that the conduction type of the oxide supports critically influences the catalytic efficiency via charge density control of metallic sites. In general, an n‐type semiconductor enhances the catalytic performance while a p‐type reduces the catalytic activity in the presence of suitable illumination conditions. Further investigation on the Pd tetrahedron‐TiO2 nanosheet hybrid structure reveals that Heck reactions take place via a radical intermediate mechanism in the presence of light, leading to a significant increase in the catalytic performance.

Control of selectivity in organic synthesis via heterogeneous photocatalysis under visible light

“…Impressively, a variety of organic reactions have been successfully driven by diverse heterogeneous photocatalysts, such as the Suzuki coupling [64], Heck reaction [65], α-alkylation of aldehydes [66], epoxide alcoholysis [67,68], Diels-Alder cycloaddition [69], fatty acid decarboxylation [70] and Aldol condensation [71]. In comparison with the above-mentioned reactions, we will focus on the typical redox types in this review, which involve a few intermediates during the oxidation and reduction processes.…”

Enhancing the Catalytic Activity of Pd Nanocrystals towards Suzuki Cross‐Coupling by g‐C3N4 Photosensitization

“…Cross-coupling reactions are versatile and powerful tools for carbon-carbon bond formation which can be utilized to synthesize organics for pharmaceuticals, biaryl compounds, natural products etc. [1][2][3][4][5][6] In the Suzuki cross-coupling process, less reactive functionalized aryl halides engage with benign boronic acids, known for their stability against heat and moisture, as well as their non-toxic nature. This confers practical advantages when compared to other CÀ C coupling methods.…”

“…This confers practical advantages when compared to other CÀ C coupling methods. [6] Typically, Suzuki coupling reactions employ homogeneous catalysts, often featuring palladium combined with phosphine ligands. These catalysts have exhibited noteworthy activity and selectivity.…”

“…In the Suzuki cross‐coupling process, less reactive functionalized aryl halides engage with benign boronic acids, known for their stability against heat and moisture, as well as their non‐toxic nature. This confers practical advantages when compared to other C−C coupling methods [6] . Typically, Suzuki coupling reactions employ homogeneous catalysts, often featuring palladium combined with phosphine ligands.…”