Catalytic Friedel–Crafts allylation using Zn(II) triflimidate

Metal Triflimidates: Better than Metal Triflates as Catalysts in Organic Synthesis—The Effect of a Highly Delocalized Counteranion

“…Similar results were obtained with Ni(NTf 2 ) 2 . [157] The gold-catalyzed cyclization of arenes tethered to an alkyne generally proceeds by an n-endo-dig cyclization process, and represents a powerful tool for the synthesis of fused (hetero)bicyclic unsaturated compounds such as chromenes, 1,2-dihydroquinolines, and related compounds. [158] The mechanism of these reactions seems well established and, in contrast to the above Friedel-Crafts reactions, competitive Brønsted acid catalysis [156] is unlikely since the proton source is mainly involved in the key protodeauration step that regenerates the gold catalyst and also because Brønsted superacids (AH) are less efficient alkyne activators than their gold(I) salts [LAu]·A.…”

Metalltriflimidate sind bessere Katalysatoren für die organische Synthese als Metalltriflate – der Effekt eines stark delokalisierten Gegenions

“…¾hnliche Ergebnisse wurden mit Ni(NTf 2 ) 2 erhalten. [157] Die goldkatalysierte Cyclisierung von Aren-Alkinen verläuft allgemein als n-endo-dig-Cyclisierung und stellt eine effiziente Methode für die Synthese von anellierten (hetero)bicyclischen ungesättigten Verbindungen wie Chromenen oder 1,2-Dihydrochinolinen dar. [158] Im Unterschied zu den bereits behandelten Friedel-Crafts-Reaktionen scheint für diese Reaktionen eine konkurrierende Katalyse durch Brønsted-Säure [156] [162] dies war der erste experimentelle Nachweis für die rechnerisch vorhergesagten diaurierten Reaktionsintermediate.…”

InIII‐Catalysed Tandem C–C and C–O Bond Formation between Phenols and Allylic Acetates

“…The reactions were performed with a 1a/2a ratio of 10:1 in the presence of 1 mol-% of the catalyst in dichloromethane at room temperature. Zn(NTf 2 ) 2 , recently reported for the allylation of aryl derivatives with allylic acetates, [14] was inefficient for the tandem allylation-cyclisation reaction starting from phenol ( (Table 1, Entries 8 and 9). Moreover, controlling the concentration of acid is crucial to avoid substrate polymerisation.…”