Copper-Catalyzed Formal [4 + 1] Annulation of Diynes with Isoxazoles: Synthesis of Pyrrolo[3,4-b]indoles

Organic Letters, Год журнала: 2025, Номер unknown

Опубликована: Май 14, 2025

Catalytic annulation of isoxazoles with alkynes is an efficient methodology for the assembly N-heterocyclic architectures, and most reactions require noble-metal catalysts. Herein, we disclose a copper-catalyzed formal [4 + 1] 1,6-diynes atom-economical construction biologically important pyrrolo[3,4-b]indoles in high yields via vinyl cation intermediates, which significantly different from previous annulations involving α-imino metal carbene intermediates. Interestingly, preliminary results have been obtained related catalytic atroposelective transformation. Computational mechanistic studies are employed to elucidate reaction mechanism.

Язык: Английский

Ligand‐Dependent Chemoselectivity in Gold‐Catalyzed Reactions between Anthranils and Diynamides. Formation of Spiro Azacyclic Compounds versus 1‐Imino‐1H‐Indene‐3‐Carboximidamides

ChemistryEurope, Год журнала: 2025, Номер unknown

Опубликована: Май 24, 2025

Gold‐catalyzed reactions between anthranils and diynamides have been investigated, their reaction chemoselectivity relies on the types of gold catalysts. With same anthranil/diynamide mixtures, use PPh 3 AuCl/AgNTf 2 leads to formation spiro azacyclic compounds, whereas P( t ‐Bu) ( o ‐biphenyl)AuCl/AgNTf preferably yields 1‐imino‐1 H ‐indene‐3‐carboximidamides instead. In system, an indole intermediate at low temperature for X‐ray diffraction study is isolated; this isolable species requires anthranil catalyst efficient products. case , mechanism its resulting postulated based literature reports.

Язык: Английский