Catalytic Friedel–Crafts Acylation Reactions

Electrospun Gelatin Membrane Cross-Linked by a Bis(diarylcarbene) for Oil/Water Separation: A New Strategy To Prepare Porous Organic Polymers

“…As shown in Scheme 1, 4-phenoxyaniline was reacted with 1 H ,1 H ,2 H ,2 H -perfluorooctyl iodide to give compound 1 , which was subsequently reacted with trifluoroacetic anhydride (TFAA) to give amide 2 , and converted to ketone 3 by Friedel–Crafts reaction. 38 The ketone group of 3 was treated with hydrazine monohydrate to give hydrazone 4 , which was oxidized with MnO 2 to give bis(diaryldiazomethane) 5 . The reactivity of diazomethane 5 was assessed by treatment with acetic acid and compared with the reported diazomethanes, before being used for modification.…”

“…This provides a new way to prepare absorbent materials for oil/ water separation and further expands the application of carbene chemistry in materials, which have already been used for the introduction of color, 29,30 hydrophobicity, 31,32 antibacterial activity, 33,34 fluorescence, 35 and payload delivery. 36,37 38 The ketone group of 3 was treated with hydrazine monohydrate to give hydrazone 4, which was oxidized with MnO 2 to give bis(diaryldiazomethane) 5. The reactivity of diazomethane 5 was assessed by treatment with acetic acid and compared with the reported diazomethanes, before being used for modification.…”

Sc(OTf)3-Catalyzed Cyclization of Allyl Amides of Ethenetricarboxylate

“…1 H NMR (400 MHz, CDCl 3 ): δ = 1.26 (t, J = 7.1 Hz, 3 H), 1.30 (t, J = 7.1 Hz, 3 H), 2.34 (br. s, 1 H), 2.60 (ddtd, J = 8.9, 6.8, 5.9, 5.7 Hz, 1 H), 2.86 (d,J = 0.6 Hz,3 H),2.91 (dd,J = 6.8,4.1 Hz, 1 H), 3.20 (dd, J = 9.8, 5.7 Hz, 1 H), 3.46 (dd, J = 9.8, 8.9 Hz, 1 H), 3.65 (d, J = 5.9 Hz, 2 H), 4.07 (d,J = 4.1 Hz,1 H),4 H).…”

“…3 More atom-economical processes for those reactions are of considerable interest and some catalytic methods have been reported. [4][5][6] Nitrogen-containing five-membered heterocycles such as pyrrolidines are important motifs found in many natural products and pharmaceuticals. 7 A number of reactions have been reported for the construction of pyrrolidines.…”

Substrate-Controlled Regiodivergent Synthesis of Fluoroacylated Carbazoles via Friedel–Crafts Acylation

“…As key structural motifs, trifluoromethylated organic compounds have received intensive attention in recent years, due to their importance in various fields such as pharmaceutical industries, agrochemical processes, and material science. − Given this perspective, the development of new strategies for introduction of trifluoromethyl moieties into organic frameworks would also be highly desirable, and many efforts have been devoted to their constructions. − On the other hand, Friedel–Crafts acylation reactions have been the most common method for the functionalization of aromatic ring systems. − Among the nitrogen-containing aromatic heterocycles, Friedel–Crafts-type trifluoroacetylation of indoles has been well established, − whereas the Friedel–Crafts-type trifluoroacetylation of carbazoles is still a challenging goal, and only a few examples have been reported with very limited chemoselectivity and substrate scope. − As our continued interest in the chemistry of carbazole, we herein present a general and divergent protocol to access versatile trifluoroacetylated carbazoles (Scheme ). In this methodology, readily available carbazoles, trifluoroacetic acid, and trifluoroacetic anhydride proceeded smoothly under an air atmosphere to give various trifluoroacetylated carbazoles according to different substituents on carbazoles with good yields and broad substrate scope without using any metal catalyst.…”