Coinage (Au, Ag, Cu) metal-catalyzed (3 + 2) annulation of α-aminoketones and electron-deficient alkynes as a route to 3-EWG-substituted pyrroles

• Published in: Catalysis science & technology Vol. 14; no. 19; pp. 5671 - 5677
• Main Authors: Chikunova, Elena I., Kotikova, Polina F., Dar'in, Dmitry V., Kukushkin, Vadim Yu, Dubovtsev, Alexey Yu
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 30.09.2024
• Subjects: Alkynes; Catalysts; Catalytic converters; Chemical reactions; Copper; Functional groups; Gold; Organic chemistry; Pyrroles; Silver; Substitutes
• ISSN: 2044-4753; 2044-4761
• DOI: 10.1039/D4CY00660G

Coinage (Au, Ag, Cu) metal-catalyzed (3 + 2) annulation of α-aminoketones and electron-deficient alkynes provides a modular one-step route to a variety of 3-EWG-substituted pyrroles. Apart from gold( i ) complexes, which “open any door” and catalyze the annulation regardless of the identity of the alkyne EWGs [–SO 2 R, –CO 2 R, –PO(OR) 2 ], the other cheaper coinage metal (first of all Cu, but also Ag) species function as alternative catalysts for the selective activation of alkynylsulfones and their conversion to 3-sulfonylpyrroles. The developed catalytic annulation operates under relatively mild conditions (5 mol% of a coinage metal catalyst, DCE, 80 °C) and provides a high functional group tolerance (36 examples; yields up to 99%). The synthetic utility of the obtained products was illustrated by practical post-modification of either the pyrrole backbone, or the peripheral substituents.