The wavelength-regulated, photoredox-catalyzed stereodivergent synthesis of (Z)- and (E)-1,4-enediones from phosphonium ylides is reported.

In the present paper, we report an efficient total synthesis of a marine alkaloid, rigidin E. The key tetrasubstituted 2-amino-3-carboxamidepyrrole intermediate was synthesized by cascade Michael addition/intramolecular cyclization between N-(2-(4-(benzyloxy)phenyl)-2-oxoethyl)methanesulfonamide and 3-(4-(benzyloxy)phenyl)-2-cyano-N-methylacrylamide. Subsequent carbonylation with triphosgene catalyzed by I₂ and deprotection of benzyl groups afforded rigidin E in 21% overall yield. This strategy has the merits of metal-free reactions, low cost, mild reaction protocols, and easy access to diversity-oriented derivatives for potential structure-activity relationship investigation.

2D layered photocatalysts with proper electronic structure have sparked much attention in the field of visible-light photocatalysis for H₂ production. Herein, by simply calcining the mixture of ultrathin g-C₃N₄ (CNN) and NaBH₄, heteroatom B and N defect were simultaneously introduced into g-C₃N₄. The obtained modified g-C₃N₄ (BDCNN) was further coupled with 2D flower-like CdS nanosheet. The optimal 2D/2D BDCNN/CdS-15% heterojunction behaved ideal photocatalytic activity for H₂ revolution by water splitting, and the highest H₂ revolution rate was as high as 1013.8 μmol g⁻¹ h⁻¹, which was 6.7 times, 2 times, and 5.8 times of the corresponding values of pristine CNN, BDCNN and CdS respectively. It was evidenced that the band structure of 2D/2D BDCNN/CdS-15% was well tuned for better visible-light adsorption and higher separation efficiency of photo-induced carriers for enhancing H₂ revolution performance. The achievement in this study provided informative principles for exploring g-C₃N₄ based heterojunctions with higher H₂-production performance.

In this study, carbonized silicon carbide/graphitic carbon nitride ((SiC/C)/g-C ₃ N ₄ ) composites were fabricated via a facile calcination method. The optimal SiC/C/g-C ₃ N ₄ composite shows an excellent visible-light photocatalytic activity for water splitting, with the highest hydrogen evolution amount being 200.2 μ mol, which is four times higher than that of pure g-C ₃ N ₄ when triethanolamine and platinum (1.0 wt%) are used as the sacrificial agent and cocatalyst, respectively. With an intimate interface between SiC/C and g-C ₃ N ₄ , the energy band structure of g-C ₃ N ₄ was well engineered for photocatalytic H ₂ production. This study provides a novel method for fabricating g-C ₃ N ₄ -based heterojunctions for application in environmental conservation.

Photocatalysts with heterojunction structure have been widely used for organic degradation. In this study, CuS/g-C₃N₄ heterojunction was formed by in situ self-assembly via a simply hydrothermal method. A series of characterizations were applied to analyzing the morphology, structure, optical properties and photo-induced electron transfer of the samples. The effect of CuS mass ratio in the CuS/g-C₃N₄ composite on methyl blue (10 mg l⁻¹) degradation under visible-light illumination was discussed. When CuS mass ratio was 60%, CuS/g-C₃N₄ behaved the highest photocatalytic efficiency which is 17 times higher than that of pure g-C₃N₄, and the optimal heterojunction exhibited promising photocatalytic stability as well. The synthesized CuS/g-C₃N₄ with intimate contact and promising photocatalytic performance provides important implications on analogous researches on g-C₃N₄-based heterojunctions for photocatalytic applications.