Silver-catalyzed direct couplings of 2-substituted furans with cyclic 1,3-dicarbonyls

Hidden Brønsted Acid Catalysis: Pathways of Accidental or Deliberate Generation of Triflic Acid from Metal Triflates

“…Several literature reports suggest the use of AgOTf as a catalyst in halogenated organic solvents including 1,2-dichloroethane (hereafter abbreviated DCE), often at elevated temperatures. ,− This is potentially problematic in view of the halide abstracting properties of the silver cation . To investigate the stability of silver triflate in DCE, we heated a sample of the compound at reflux (84 °C) for 3 h. The resulting turbid suspension was filtered to leave an almost quantitative yield (99%) of AgCl on the filter (for a photograph; see Figure S1, Supporting Information).…”

Alternative Synthetic Methods through New Developments in Catalysis by Gold

“…Higher reactivity of silver salts was shown for the functionalization of furans. 209 The method allows high functional group tolerance, regioselectivity, and scope under relatively mild conditions. The 3-alkenylindoles 210 can also be readily available through gold-catalyzed sequential cyclization/alkenylation reaction of 2-alkynylanilines 209 with 1,3-dicarbonyl compounds.…”

“…Both gold(III) and silver(I) precatalysts have similar reactivity in the alkenylation reaction of pyrroles. Higher reactivity of silver salts was shown for the functionalization of furans …”

Alkenylation Reactions of Heteroarenes by Transition-Metal Catalysts

“…Finally, it should be noted that, in 2007, an unusual silvercatalyzed alkenylation reaction of electron-rich heteroarenes was used by Arcadi and co-workers. 50 tive method for the synthesis of alkenyl-substituted heteroarenes that bypasses the need for preactivated reaction partners. In many cases, these reactions, which have significantly enriched the field of organic synthesis, have proven to be highly chemo-, regio-and stereoselective.…”