Reduced Graphene Oxide as Recyclable Catalyst for Synthesis of Bis(aminothiocarbonyl)disulfides from Secondary Amines and Carbon Disulfide

Thiuram Disulfide Mediated Cu-Catalyzed Amidation of Terminal Alkynes: An Efficient Synthesis of Alkynyl Amides

Terminal alkynes undergo a CO-free aminocarbonylation reaction mediated by thiuram disulfides. Thiuram disulfide acts as the source of the carbamoyl group in the amidation of terminal alkynes in the presence of copper-based reagent and catalyst. A series of alkynyl amides has been prepared with several structural variations following the current one-pot two-step protocol. The reaction proceeds through a mixed disulfide intermediate, which has been isolated and characterized by single-crystal XRD analysis.

Reaction Pathway and Selectivity Control of Tetraethyl Thiuram Disulfide Synthesis with NaHCO3 as a pH Regulator

The selectivity of a chemical reaction is related to the effective utilization of raw materials as well as the cleanliness and economy of the process. Herein, it has been first proposed to synthesize tetraethyl thiuram disulfide (TETD) with sodium bicarbonate as the pH regulator with a reaction selectivity of ∼100%. The existence of a reaction intermediate, a sodium salt of diethyl dithiocarbamoylsulfenic acid (NaEt₂DTCS), has been proved by experiments and theoretical calculations. The results indicate that TETD can not only be generated from NaEt₂DTCS oxidized by H₂O₂ directly, but also from the conjugation of NaEt₂DTC and NaEt₂DTCS generated in the first stage of oxidation meanwhile. Accordingly, an oxidation reaction pathway has been proposed. The reaction selectivity with NaHCO₃ or CO₂ as the pH regulator has been compared, and the selectivity control mechanism is discussed. At relatively higher pH values with NaHCO₃ as the pH regulator, peroxidation could be almost avoided.

Modulating the electronic and magnetic properties of graphene

Graphene, an sp²hybridized single sheet of carbon atoms organized in a honeycomb lattice, is a zero band gap semiconductor or semimetal.

Graphene oxide–TiO2 composite: an efficient heterogeneous catalyst for the green synthesis of pyrazoles and pyridines

GO–TiO₂ has been found to be a highly efficient and recyclable heterogeneous catalyst for the synthesis of pyrazoles and pyridines in aqueous medium at room temperature.

Metal-free one-pot synthesis of amides using graphene oxide as an efficient catalyst

Graphene oxide was found to be a highly efficient carbocatalyst for one-pot synthesis of amides from aromatic aldehydes and secondary amine.