Green and Practical Synthesis of Thioenamines and Chromones via Iodine-Catalyzed Cross-Dehydrogenation Coupling Reaction

J Org Chem. 2022 Nov 18;87(22):15350-15357. doi: 10.1021/acs.joc.2c01924. Epub 2022 Nov 8.

Abstract

An iodine-catalyzed one-pot synthesis of thioenamines and chromones is reported. By using easily available phenyl isothiocyanate, alcohols, and enamines as starting materials, a tandem reaction (nucleophilic addition and the subsequent cross-dehydrogenation coupling) proceeded smoothly to give the desired thioenamines in good to excellent yields. This protocol features simple operation, mild conditions, a broad substrate scope, good atomic economics, and no need to add extra reaction solvents, providing a practical and green route for the synthesis of thioenamines. In addition, this method can also prepare some representative chromones in moderate yields.