Sustainable production of triazoles from lignin major motifs.

An efficiently catalyzed synthesis of pharmaceutically relevant 1,2,3-trazoles from renewable resources is highly desirable. However, due to incompatible catalysis conditions, this endeavor remained challenging so far. Herein, a practical access protocol to 1,2,3-triazoles, starting from lignin phenolic β-O-4 with γ-OH group utilizing a vanadium-based catalyst is presented.

Towards bioresource-based aggregation-induced emission luminogens from lignin β-O-4 motifs as renewable resources.

One-pot synthesis of heterocyclic aromatics with good optical properties from phenolic β-O-4 lignin segments is of high importance to meet high value added biorefinery demands. However, executing this process remains a huge challenge due to the incompatible reaction conditions of the depolymerization of lignin β-O-4 segments containing γ-OH functionalities and bioresource-based aggregation-induced emission luminogens (BioAIEgens) formation with the desired properties. In this work, benzannulation reactions starting from lignin β-O-4 moieties with 3-alkenylated indoles catalyzed by vanadium-based complexes have been successfully developed, affording a wide range of functionalized carbazoles with up to 92% yield.

Performance Evaluation and Oil Displacement Effect of Amphiphilic Polymer Heavy Oil Activator.

A heavy oil activator is an amphiphilic polymer solution that contains hydrophilic and oleophobic groups. It can enhance heavy oil recovery efficiency. This paper studied the changes in the distribution of the remaining oil after activator flooding and the performance of heavy oil's active agent.

Transition-Metal-Free Synthesis of Functionalized Quinolines by Direct Conversion of β-O-4 Model Compounds.

Direct production of heterocyclic aromatic compounds from lignin β-O-4 models remains a huge challenge due to the incompatible catalysis for aryl ether bonds cleavage and heterocyclic ring formation. Herein, the first example of quinoline synthesis from β-O-4 model compounds by a one-pot cascade reaction is reported in yields up to 89 %. The reaction pathway involves selective cleavage of C-O bonds, dehydrogenation, aldol condensation, C-N bond formation along with heterocyclic aromatic ring construction.

Transition-metal-free synthesis of pyrimidines from lignin β-O-4 segments via a one-pot multi-component reaction.

Heteroatom-participated lignin depolymerization for heterocyclic aromatic compounds production is of great importance to expanding the product portfolio and meeting value-added biorefinery demand, but it is also particularly challenging. In this work, the synthesis of pyrimidines from lignin β-O-4 model compounds, the most abundant segment in lignin, mediated by NaOH through a one-pot multi-component cascade reaction is reported. Mechanism study suggests that the transformation starts by NaOH-induced deprotonation of Cα-H bond in β-O-4 model compounds, and involves highly coupled sequential cleavage of C-O bonds, alcohol dehydrogenation, aldol condensation, and dehydrogenative aromatization.

Copper-Catalyzed Three-Component Formal [3 + 1 + 2] Benzannulation for Carbazole and Indole Synthesis.

Three-component formal [3 + 1 + 2] benzannulation reactions of indole-3-carbaldehydes or 1-methyl-pyrrole-2-carbaldehydes with two different molecules of saturated ketones have been successfully developed under Cu-catalyzed and 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-mediated conditions. Various unsymmetrically substituted carbazoles and indoles were obtained up to 95% yield. Furthermore, the resulting products exhibit unusual aggregation-induced emission (AIE) properties in the solid state.

High-Loading Single-Atom Copper Catalyst Supported on Coordinatively Unsaturated Al O for Selective Synthesis of Homoallylboronates.

Single-atom catalysts (SACs) as a bridge between hetero- and homogeneous catalysis have attracted much attention. However, it is still challenging to generate stable single atoms with high metal loadings, and the application of SACs in traditionally homogeneous catalytic reactions is highly desirable. Herein, a Cu SAC with a high Cu loading of 8.