One-Pot Gold-Catalyzed Aminofluorination of Unprotected 2‑Alkynylanilines

A tandem gold(I)-catalyzed aminocylization/fluorination and a two-step, one-pot gold(III)-catalyzed cyclization/electrophilic fluorination provide a convenient and general method for the synthesis of 3,3-difluoro-2-substituted-3<i>H</i>-indoles in good yield under mild conditions. Extension of the procedure to the synthesis of 2-aryl-3-fluoro-1<i>H</i>-indoles is described. The reaction proceeds smoothly in green ethanol and does not require any base, acid, or <i>N</i>-protective group

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