Microwave-Assisted Facile and Rapid Friedel–Crafts Benzoylation of Arenes Catalyzed by Bismuth Trifluoromethanesulfonate

A Simple, Effective, Green Method for the Regioselective 3-Acylation of Unprotected Indoles

“…The slightly lower yields of 3-acylated products are due to increased substitution at the 1-and 2-position (Table 3, entries 7-18). However, acylation of 4-or 5-haloindoles with aliphatic acid anhydrides produced 3-acylindoles in good yields (Table 3, entries [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34]. In addition, N-acylated byproducts were slightly decreased in comparison with electron-rich indoles, but 2-acylindoles were obtained in small amounts (Table 3, entries [19][20][21][22][23][24][25][26][27][28][29].…”

“…Although metal triflates have been applied extensively in Friedel-Crafts acylation of aromatic compounds [24][25][26][27][28], there has been only one report on the use of indium triflate for the acylation of indoles [29]. However, in that case, excess reagent and NH-protection were required to obtain 3-acylated indoles in good yields.…”

Mechanism of Friedel–Crafts Acylation Using Metal Triflate in Deep Eutectic Solvents: An Experimental and Computational Study

“…Metal triflates, water-compatible Lewis acids, have increased interest in organic synthesis. − Metal triflates are considered green catalysts for alternative traditional Lewis acids due to their strong Lewis acidity and high tolerance toward water. − Metal triflates can be used with organic solvents or water, and they are easily recycled without a decrease in catalytic activity. − Metal triflate has been known as an effective catalyst for Friedel–Craft transformation in the past 2 decades. ,− While there is the conventional understanding that Lewis acid is a stoichiometric requirement for the reaction and metal cation can fill this role, triflate anion also is crucial. − Currently, our theory study highlights that triflate helps stabilize the acylium and accommodate kinetic accessible pathways in the C–C bond formation process . However, the details of how this species is formed under the support of Lewis acid are still unexplored, especially when extending the list to rare-earth metals.…”

An Efficient and Green Synthesis of 1‐Indanone and 1‐Tetralone via Intramolecular Friedel–Crafts Acylation Reaction

“…[5,[7][8][9][10] Metal triflates are efficient and green catalysts for Friedel-Crafts acylation. [11][12][13][14][15][16][17][18][19][20][21][22] Recently, metal-triflate-catalyzed Friedel-Crafts acylation with carboxylic acids as the acylating reagents has been studied extensively. [23][24][25][26][27] Although the intramolecular Friedel-Crafts acylation of carboxylic acids has been catalyzed by metal triflates with only 5-10 %c atalytic loading, the requirement for volatile organic solvents and long reactiont imes are current shortcomings.…”