Search

A sustainable strategy based on chitin from waste seafood is proposed to remove nano‐size microplastics in water. A chitin nanofibrous foam is constructed by a new hydrogen bond rearrangement scheme without any crosslinking, which delivers an impressive high adsorption capacity of 411.14 ± 1.50 mg g−1 for small‐sized (< 1 µm) microplastics. This excellent adsorption capacity stems from the rough fibrous surface structure of the highly porous foam, the positively charged nature of the partially deacetylated chitin and other molecular interactions introduced by the activation and increased exposure of ‐OH, ‐NH2 and ‐NHCO‐ groups. Molecular dynamics simulation further demonstrates that C‐H‐π, O‐H‐π, and C = O‐π interactions between the microplastics and chitin foam facilitates the efficient removal of microplastics. A high removal efficiency is maintained even in salty water, a property that exemplifies good adaptability to various water bodies. Finally, two proof‐of‐principle scenarios are presented for converting the recovered microplastics into value‐added products. Thus, the entire cycling strategy represents a powerful remedy for the urgent yet challenging ocean microplastic pollution problem. [ABSTRACT FROM AUTHOR]

Abstract: A PdII‐catalyzed oxidative tandem cyclization was developed for the construction of fused 5,6‐bicyclic N, O‐heterocycles. This reaction was enabled by the combined use of a 3‐methylpyridine ligand and pentafluorobenzoic acid additive. A range of heterocyclic products with different substituents could be prepared in moderate to good yields via this methodology. Several transformations, including a scaled‐up preparation of product 2 a, were also carried out showing the good applicability of our methodology. [ABSTRACT FROM AUTHOR]

A Pd(II)-catalyzed oxidative cyclization of olefinic tosylamides was developed for the preparation of aryl-fused and N-containing six-membered heterocycles. Under optimized conditions the reaction proceeded with high activity and selectivity, with yields of up to 83% being obtained. This procedure provides a facile and efficient route to the aforementioned heterocycles with 2-acetoxy functionality. [ABSTRACT FROM AUTHOR]

A Pd II -catalyzed oxidative tandem cyclization was developed for the construction of fused 5,6-bicyclic N, O-heterocycles. This reaction was enabled by the combined use of a 3-methylpyridine ligand and pentafluorobenzoic acid additive. A range of heterocyclic products with different substituents could be prepared in moderate to good yields via this methodology. Several transformations, including a scaled-up preparation of product 2 a, were also carried out showing the good applicability of our methodology., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)