A Four-Component Reaction for the Synthesis of Thienopyrrolediones under Transition Metal Free Conditions.

A three-starting-material four-component reaction strategy is described to construct thienopyrrolediones (TPDs) from the simplest raw materials, elemental sulfur, aldehydes, and ß-ketoamides, under transition metal free conditions. Compared with traditional multistep reaction sequences, this process is simple, efficient, environmentally friendly, and atom-economic and has laid the foundation for further development of an easily synthesized TPD unit.

Acid-catalyzed three-component addition of carbonyl compounds with 1,2,3-triazoles and indoles.

A facile and efficient acid-catalyzed three-component reaction of indoles, 1-tosyl-1,2,3-triazoles and carbonyl compounds has been developed. The use of TsOH with a small amount of water significantly promoted the reaction yield. This method provided a general and one-pot approach for the synthesis of structurally diverse C3-alkylated indole derivatives. The alkylation exclusively occurred at the N2 position of triazoles. Various functional groups were tolerated under the optimized simple reaction conditions.

Iron-Promoted Three-Component 2-Substituted Benzothiazole Formation via Nitroarene ortho-C-H Sulfuration with Elemental Sulfur.

A three-component procedure for the preparation of 2-substituted benzothiazoles from nitroarenes, alcohols, and sulfur powder is described. The reaction showed a good functional group tolerance to provide the heterocyclic products in moderate to good yields. The sequential assembly involving nitro reduction, C-N condensation, and C-S bond formation has been realized in one pot.