Trifluoromethanesulfonic Acid as Acylation Catalyst: Special Feature for C- and/or O-Acylation Reactions

Abstract

Trifluoromethanesulfonic acid (TfOH) is one of the superior catalysts for acylation. The catalytic activity of TfOH in C-and/or O-acylation has broadened the use of various substrates under mild and neat or forced conditions. In this review, the salient catalytic features of TfOH are summarized, and the unique controllability of its catalytic activity in the tendency of C-acylation and/or O-acylation is discussed.

Synthesis of Chiral TFA-Protected α-Amino Aryl-Ketone Derivatives with Friedel–Crafts Acylation of α-Amino Acid N-Hydroxysuccinimide Ester

“…Compared with the acylation of aryl N -hydroxysuccinimide ester derivatives and electron-rich arenes, such as ferrocene and pyrene [ 17 ], l -/ d - 1b and l -/ d - 2b are reactive in relatively electron-poor acyl acceptors of benzene when conventional AlCl 3 is used. Thus, the activation is not necessary under harsh conditions, such as utilization of super acidic trifluoromethanesulfonic acid [ 5 , 6 ]. Moreover, l -/ d - 1b and l -/ d - 2b can dissolve well in benzene and thus, no solvent is needed for the reaction system.…”

“…Chiral N -protected α-amino aryl-ketone are usually used as a precursor in the synthesis of various biologically active compounds [ 1 , 2 ]. The most favorable strategy to synthesize α-amino aryl-ketone is by Friedel–Crafts acylation [ 3 , 4 ] of arenes, which is known as a reliable method that results in satisfactory product yields [ 5 ] and can utilize convenient optically pure α-amino acid derivatives as skeletons [ 6 ]. The α-amino acid chloride [ 1 , 2 , 7 , 8 ] is widely used as an acyl donor to undergo Friedel–Crafts acylation due to its reactivity.…”

Chalcones and Chalcone-mimetic Derivatives as Notch Inhibitors in a Model of T-cell Acute Lymphoblastic Leukemia

“…The trimethoxy derivative 14 was obtained in low yield probably due to steric hindrance. However, the direct acylation reaction of the fluoroarene 20d with the acid 19a by adapting previous reports using TFAA/TfOH, 19,20 allowed the formation of the regioisomers 15 and 16, as shown in Scheme 1. Similarly, reaction of the 7-methoxychromane-3-carboxylic acid 19b or 7-methoxy-1,2,3,4-tetrahydronaphthalene-2-carboxylic acid 19c with 20a in the presence of TFAA/TfOH afforded the aryl derivatives 17 and 18 in 38% and 73% yield, respectively.…”

Werner transition‐metal complex (WTMC)‐mediated mild and efficient chemo‐selective acylation of phenols and anilines under solvent‐free condition

“…The acylation of alcohols, phenols, and amines is catalyzed with a variety of catalysts such as cobalt chloride (CoCl 2 ), Sc(OTf) 3, TaCl 5, montmorillonite K10, HY zeolite, In(OTf) 3, Cu(OTf) 2, silica gel‐supported sulfuric acid, yittria/zirconia‐based Lewis acid, InCl 3 /Mont. K 10, sodium dodecyl sulfate (SDS), ammonium acetate in acetic acid, manganese (III) bis(2‐hydroxyanil)acetylacetonato complex,silica sulfate, p ‐MeC 6 H 4 SO 2 NBr 2, DBDMH or TCCA, ZnCl 2, H 6 P 2 W 18 O 62 · 24H 2 O, vanadyl sulfate, La(NO 3 ) 3 · 6H 2 O, 2,4,6‐triacyloxy‐l,3,5‐triazine (TAT), zinc dust,ionic liquid based on morpholin, borated zirconia, DMAP‐saccharin, copper‐catalyzed azidation reaction of anilines(primary amine), acylation of phenol and salicylic acid in the presence of zirconium phosphate (ZP) nanoparticles, oxidative acylation of phenols with N ‐heteroarylmethanes under transition metals, N ‐alkylation of amines with alcohols in presence of PNP manganese pincer complexes, trifluoromethanesulfonic acid (TfOH)‐catalyzed acylation of phenol and its derivaties, bacterial acyltransferase acylation of phenolic compounds, and acylation of BN‐arenes using BN‐arene and acyl chloride in order to synthesize the indanone BN‐analog . The disadvantages of all the above methods are their high cost, vigorous reaction condition, toxicity of the reagent, poor yield, instability, hygroscopic nature of the reagent, and tedious work‐up procedures.…”