A Convenient Trifluoroacetylation of Arenes with 2-(Trifluoroacetoxy)pyridine

Abstract

2-(Trifluoroacetoxy)pyridine (TFAP) is useful for trifluoroacetylating arenes under the Friedel–Crafts conditions. Benzene, alkylbenzenes, naphthalene, and dibenzofuran have reacted with TFAP in the presence of aluminum chloride in dichloromethane to give the corresponding trifluoromethyl aryl ketones in good isolated yields.

Expedient synthesis of [18F]‐labeled α‐trifluoromethyl ketones

“…7,8 Recently we reported the direct preparation of simple TFMKs from carboxylic esters with (trifluoromethyl)trimethylsilane (TMS-CF 3 ). 9 This method has been further extended by others with CsF catalyzed trifluoromethylation of esters.…”

Direct Preparation of Trifluoromethyl Ketones from Carboxylic Esters: Trifluoromethylation with (Trifluoromethyl)trimethylsilane

“…Methods for the synthesis of trifluoromethyl ketones are scarce. [2] While trifluoromethyl aryl ketones can be obtained by Friedel ± Crafts acylations, [3] alicyclic and aliphatic trifluoromethyl ketones are usually available only by multistep synthetic operations. [4,5] This restricts their use and makes it difficult to handle complicated intermediates for pharmacologically interesting targets.…”

“…[9] When a-keto esters are used as substrates in THF, TMS-CF 3 adds only to the keto group to give derivatives of Moshers acid. [10] Simple unactivated esters are unreactive toward TMS-CF 3 [11] in THF. We now report on the first successful nucleophilic trifluoromethylation of esters with TMS-CF 3 .…”

“…[10] Simple unactivated esters are unreactive toward TMS-CF 3 [11] in THF. We now report on the first successful nucleophilic trifluoromethylation of esters with TMS-CF 3 . This provides a straightforward and powerful synthetic tool to convert the ester functionality into the trifluoromethylcarbonyl group in one step without formation of double-addition products.…”

“…Different models have been developed to describe the formation of MCM-41. Beck et al [2] proposed several possible pathways for the formation of such materials, and a more detailed, mechanistic model was presented by Monnier et al [3] to account for the observation of an intermediate layered phase prior to reaching the hexagonal phase. This model introduced multidentate binding of silicate oligomers, preferred polymerization of silicate at the surfactant ± silicate interface, and charge density matching as key factors in the formation of a surfactant ± silicate mesophase.…”