Gold-Catalyzed syn-1,2-Difunctionalization of Ynamides via Nitrile Activation

Gold(I)‐Catalyzed [8+2]‐Cycloaddition of 8‐Aryl‐8‐azaheptafulvenes with Allenamides and Ynamides: Regioselective Synthesis of Dihydrocycloheptapyrrole Derivatives

“…According to these results and previous gold‐catalyzed ynamide cycloadditions, our proposed mechanism would start from the nucleophilic attack of the azaheptafulvene nitrogen to the α‐carbon of the gold keteneinimium intermediate II [23] followed by intramolecular cyclization of IV to intermediate V and regeneration of the gold catalyst, to give 7 after hydrogen 1,5‐shift (Scheme 5).…”

Base‐Promoted Synthesis of Polysubstituted 4‐Aminoquinolines from Ynones and 2‐Aminobenzonitriles under Transition‐Metal‐Free Conditions

“…In 2017, Popowycz and co‐workers have demonstrated a multi‐step synthesis of 4‐aminoquinoline under super acidic conditions (Scheme 1b) [17] . Recently, Sahoo et al., developed the synthesis of 4‐aminoquinoline from ynamides with 2‐aminobenzonitriles via Au(I)‐catalyzed nitrile activation (Scheme 1c) [18] …”

“…[17] Recently, Sahoo et al, developed the synthesis of 4-aminoquinoline from ynamides with 2-aminobenzonitriles via Au(I)-catalyzed nitrile activation (Scheme 1c). [18] However, use of expensive catalyst, additive, limitation to the sensitive substrate and harsh reaction condition makes these methods less fruitful. These limitations encourage us to develop a novel practical approach to prepare highly substituted 4-aminoquinolines in one-step with a high atom-economy.…”

“…The effect of other bases was also investigated. For example, Inorganic bases such as Li t OBu, Cs 2 CO 3 , KOH, NaOH, K 3 PO 4 make possible the desired product 3 a in relatively lower yields (Table 1, entries [14][15][16][17][18]. Furthermore, when organic base such as DBU and DABCO was employed in the reaction, only DBU was found effective to deliver the desired product in acceptable yield (Table 1 entries [19][20].…”

Synthesis of Polycyclic Quinolines by Means of Brønsted Acid Mediated Reaction of β‐(2‐Aminophenyl)‐α,β‐Ynones with Ketones

“…Significant progress has been made in term of functional group tolerance, excellent yields under mild reaction conditions and selectivity by means of transition-metal and/or Lewis acid catalysis. [4] Nonetheless, the development of versatile and effective methodologies to especially construct polyciclic quinolines via selective control of condensation patterns from readily accessible building blocks is still of significant interest. [5] β-(2-Amino-phenyl) α,β-ynones 1 are emerging as versatile building blocks for the construction of a variety of heterocyclic scaffolds.…”