Adsorptive immobilization of cadmium and lead using unmodified and modified biochar: A review of the advances, synthesis, efficiency and mechanisms.

Biochar is an environmentally friendly adsorbent material with excellent adsorption performance due to its extensive pore structure, large specific surface area, and numerous surface functional groups. It is commonly used to treat inorganic and organic pollutants. In recent years, with increasing focus on controlling soil pollution caused by heavy metals such as cadmium (Cd) and lead (Pb), the potential application of biochar has attracted much attention.

A polyfunctionalized carbon framework composite for efficient decontamination of Cr(VI) and polycyclic aromatic nitrides from acidic wastewater.

Developing multifunctional engineered adsorbents is an effective strategy for decontaminating the environment from various pollutants. In this study, a polyfunctionalized carbon-framework composite, MSC-CFM, was synthesized. The composite comprises an aromatic carbon framework enriched with various functional groups, including magnetic nanoparticles, hydroxyl, and amino groups.

Asymmetric Formal [3 + 2]-Cycloaddition of Azomethine Imines with Azlactones To Synthesize Bicyclic Pyrazolidinones.

An efficient enantioselective formal [3 + 2]-cycloaddition of azomethine imines with azlactones has been realized by using a chiral bifunctional bisguanidinium hemisalt as the catalyst. Optically active bicyclic pyrazolidinone compounds were generated under mild reaction conditions in high yields (up to 99%) with good dr (up to 88:12) and excellent ee values (up to 99%). This simple and efficient strategy provides a method to construct biologically important chiral tetrahydropyrazolo[1,2-a]pyrazole-1,7-dione derivatives bearing vicinal aza-quaternary and tertiary carbon centers.

Organocatalytic dynamic kinetic resolution of azlactones to construct chiral N-acyl amino acid oxime esters.

A direct strategy to obtain N-acyl amino acid oxime esters has been developed through the dynamic kinetic resolution of azlactones with oximes. In the presence of a chiral bisguanidinium salt catalyst, a variety of chiral N-acyl amino acid oxime esters were generated in excellent enantiomeric excesses (up to 97%) and high yields (up to 99%). The active oxime esters could be used in dipeptide synthesis.