Palladium-Catalyzed Cascade Reactions of 1‑(3-Arylprop-2-ynyloxy)-2-bromo Benzene Derivatives with Organoboron Compounds

Applications of the cascade cyclocarbopalladation reaction followed by Suzuki–Miyaura coupling reactions of the readily available aryl-substituted propargylic aryl ethers with arylboronic acid and potassium <i>trans</i>-β-styryltrifluoroborate accomplish a new versatile entry in the synthesis of benzofuran derivatives. Notably, a new approach to the challenging synthesis of C3 functionalized 2-unsubstituted benzofurans has been developed by a cyclocarbopalladation/cross-coupling/aromatization process

Synthesis of 2‑Acylindoles via Ag- and Cu-Catalyzed anti-Michael Hydroamination of β‑(2-Aminophenyl)-α,β-ynones: Experimental Results and DFT Calculations

β-(2-Aminophenyl)-α,β-ynones afforded 3-unsubstituted 2-acylindoles in good yields in the presence of 20 mol % AgOTf under (microwave) MW heating. The use CuOTf as a catalyst resulted in a similar reaction outcome, generally with a lower efficiency. This transformation represents the first example of 5-<i>endo-dig</i> cyclization of 2-alkynylanilines bearing an acyl group linked to the triple bond. By contrast with the previously reported gold-catalyzed reaction of β-(2-aminophenyl)-α,β-ynones, which resulted in the formation of dibenzo­[1,5]­diazocines through a sequential process triggered by an intermolecular hydroamination, a selective intramolecular anti-Michael hydroamination was observed in the present study by silver/copper catalysis. Density functional theory calculations on the Ag-catalyzed reaction revealed that the catalyst induces an electrostatic arrangement in the TS coherent with the experimentally observed cyclization

Synthesis of 2‑Acylindoles via Ag- and Cu-Catalyzed anti-Michael Hydroamination of β‑(2-Aminophenyl)-α,β-ynones: Experimental Results and DFT Calculations

β-(2-Aminophenyl)-α,β-ynones afforded 3-unsubstituted 2-acylindoles in good yields in the presence of 20 mol % AgOTf under (microwave) MW heating. The use CuOTf as a catalyst resulted in a similar reaction outcome, generally with a lower efficiency. This transformation represents the first example of 5-<i>endo-dig</i> cyclization of 2-alkynylanilines bearing an acyl group linked to the triple bond. By contrast with the previously reported gold-catalyzed reaction of β-(2-aminophenyl)-α,β-ynones, which resulted in the formation of dibenzo­[1,5]­diazocines through a sequential process triggered by an intermolecular hydroamination, a selective intramolecular anti-Michael hydroamination was observed in the present study by silver/copper catalysis. Density functional theory calculations on the Ag-catalyzed reaction revealed that the catalyst induces an electrostatic arrangement in the TS coherent with the experimentally observed cyclization