Copper‐catalyzed C(sp²)–C(sp) Sonogashira‐type cross‐coupling reactions accelerated by polycyclic aromatic hydrocarbons

Abstract

Copper-catalyzed Sonogashira-type reactions were dramatically accelerated by introducing a catalytic amount of polycyclic aromatic hydrocarbon additive. This novel catalytic system features low copper loading (0.5 mol% < Cu < 5 mol%), broad reaction scope and remarkable substrate tolerance. Both aromatic and aliphatic terminal alkynes as well as diverse aryl iodides were employed in this transformation, affording respectable yields of the desired products. The novel Cu(OTf) 2 /pyrene system was subsequently employed to synthesize phenylacetylene-based fluorescent compounds.

Methionine: a green and efficient promoter for copper‐catalyzed Sonogashira cross‐coupling reactions

“…They obtained coupled products using CuI (10 mol%) as catalyst and N , N ‐dimethylglycine hydrochloride salt (30 mol%) as promoter in the presence of K 2 CO 3 and DMF at 100°C in 24–36 h. Xu et al . have recently reported catalytic systems featuring low copper loading (0.5 mol% < Cu < 5 mol%) for copper‐catalyzed Sonogashira‐type reactions accelerated by a catalytic amount of additives such as polycyclic aromatic hydrocarbon or organophosphate as the ligand . They found Cu(OTf) 2 as an effective copper source in this reaction system.…”

Applications of Bond Energy‐Based Thermodynamic Analysis to the Feasibility of Unfunctionalized C−C Cross‐Coupling Reactions

“…Another SFCC method to construct arylalkynes was reported by Wei Xu et al [68] . Most Sonogashira cross‐couplings require the addition of high amounts of Cu catalysts (5‐30 mol %).…”

“…Another SFCC method to construct arylalkynes was reported by Wei Xu et al [68] Most Sonogashira cross-couplings require the addition of high amounts of Cu catalysts (5-30 mol %). Thus, the objective was to search for a more economic as well as efficient catalytic system for the coupling.…”

Emergence of Copper‐Mediated Formation of C–C Bonds

“…Recently, Gao et al described acceleration of Sonogashira‐type cross‐coupling by polycyclic aromatic hydrocarbons or by organophosphates . Aryl iodides and aliphatic or aromatic terminal alkynes led to coupling compounds in the presence of copper triflate, pyrene or organophosphate as ligand, and a base in DMF (Scheme ).…”