Herein we report the efficient and selective two-step synthesis of various 3-silyl-2-amidoindenones from easily accessible ynamides. This sequence involves a regio- and stereo-selective ...silylcyanation followed by a Houben-Hoesch type cyclization. Thanks to post-transformations, various 3-substituted 2-amidoindenones could be obtained.
A simple and selective two-step sequence is reported for the synthesis of polyfunctionalized 2-amidoindenones. Remarkably, this method achieves true structural diversity at position 3.
A synthesis to access rarely described 3-amino-5-fluoroalkylfurans has been developed by cyclization of easily accessible fluorovinamides. This method is rapid and simple and affords the desired ...furans as hydrochloride salts in quantitative or nearly quantitative yields. It is compatible with four different fluorinated groups (-CF3, -CF2CF3, -CHF2, and -CF2Cl) and a wide range of substituents on the amine.
Aryl and alkenyl halides are widely used as key intermediates in organic synthesis, particularly for the formation of organometallic reagents or as radical precursors. They are also found in ...pharmaceutical and agrochemical ingredients. In this work, the synthesis of aryl and alkenyl halides from the corresponding fluorosulfonates using commercially available ruthenium catalysts is reported. Notably, this is the first conversion of phenols to aryl halides that is efficient with chloride, bromide, and iodide. Fluorosulfonates are readily prepared using sulfuryl fluoride (SO2F2) and less expensive substitutes for triflates. Although aryl fluorosulfonates and their reactions are well known, this is the first report of an efficient coupling of alkenyl fluorosulfonates. To finish, it was demonstrated, by means of representative examples, that the reaction is possible in a one‐pot process, starting directly from phenol or aldehyde.
The relevance of aryl fluorosulfonates in coupling reactions has increased over the past decade. Surprisingly, the use and synthesis of alkenyl fluorosulfonates is still poorly described. In this paper, the advantageous use of aryl and alkenyl fluorosulfonates instead of the corresponding triflates is reported to synthesize aryl and alkenyl halides using halide salts and commercially available ruthenium catalysts.
Here we report an efficient access to high‐value N‐polyfluoroalkyl anilines, primary polyfluoroalkylamines and N,N‐bis(polyfluoroalkyl)amines, via N‐polyfluoroalkylation of sulfonamides and ...phthalimide derivatives using sulfuryl fluoride (SO2F2). The in situ formation of polyfluoroalkyl fluorosulfonates from commercially available fluorinated alcohols and economical sulfuryl fluoride is highly advantageous given that some polyfluoroalkyl halides are ozone‐depleting substances (ODS) regulated by the Montreal protocol. This general method is applied to the polyfluoroalkylation of a variety of sulfonamides, N‐sulfonyl carbamates and phthalimide with a wide tolerance of functional groups. The process thus provides viable access for industry to N‐(polyfluoroalkyl)anilines as well as primary and secondary N‐(polyfluoroalkyl)amines, which are very valuable but not easily accessible building blocks for life science applications.
N‐polyfluoroalkylation reactions are challenging due to the high cost, toxicity or environmental impact of commonly used polyfluoroalkylation reagents. We report the sulfuryl fluoride (SO2F2)‐mediated N‐polyfluoroalkylation of weakly nucleophilic nitrogen compounds from readily available fluorinated alcohols. This method opens access to a variety of N‐polyfluoroalkylated building blocks that are highly valuable for life science applications.
Efficient access to dibenzothiophene-S-oxides from differently substituted 2-bromo-diarylsulfinyl moieties using ligandless Pd(OAc)2 as the catalyst and KOAc as the base in dimethylacetamide at 130 ...°C is reported. Various dibenzothiophene-S-oxides were obtained in excellent yields.
Abstract Acyl fluorides have emerged as versatile reagents in various synthetic endeavors, offering a range of advantages over their counterparts, acyl chlorides. This study delves into the ...properties and reactivity of acyl fluorides, particularly their reaction with amines and alcohols, to elucidate their distinct characteristics. We also introduce a facile and practical synthesis of acyl fluorides from a stable solution of CF 3 O − salt. Additionally, we establish an efficient one‐pot process for the direct preparation of amides or esters from corresponding acids and amines or alcohols, showcasing the remarkable efficiency of acyl fluorides in these transformations.
After nitrogen, fluorine is probably the next most favorite hetero-atom for incorporation into small molecules in life science-oriented research. This review focuses on a particular fluorinated ...substituent, the trifluoromethoxy group, which is finding increased utility as a substituent in bioactives, but it is still perhaps the least well understood fluorine substituent in currency. The present review will give an overview of the synthesis, properties and reactivity of this important substituent.
Despite recent advances, trifluoromethoxylation remains a challenging reaction. Here we describe an efficient trifluoromethoxylative substitution, using an inexpensive and easy‐to‐handle reagent. By ...mixing DMAP with a slight excess of 1,4‐dinitro‐trifluoromethoxybenzene (DNTFB), a stable solution of trifluoromethoxide anion is obtained and can be used to perform a SN2 reaction without any silver additives. A precise study of the properties and behavior of this unusual stable solution of CF3O− species is also performed.
A stable solution of the trifluoromethoxide anion was readily obtained by mixing 2,4‐dinitro‐trifluoromethoxybenzene (DNTFB) and DMAP. A detailed study and characterization of this solution has been described, in particular highlighting the crucial role of the DNTFB/DMAP ratio. This “trifluoromethoxide anion solution” was applied to perform metal‐free SN2 reactions on alkyl bomides with yields up to 77 %.
The strongly oxidizing, powerful electrophilic fluorination reagent FXeOTf is shown to effect direct oxidative monofluorination of sulfoxides. This one‐step, chloride promoter‐free methodology ...provides access to so far inaccessible, yet highly desirable strongly Lewis acidic fluorosulfoxonium cations from electron‐deficient and/or sterically demanding sulfoxides that are shown to be practically unreactive towards the previously reported XeF2/NEt4Cl system. Experimental and density functional theory studies have been conducted to assess the Lewis acidities of the prepared sulfur(VI) cations. Preliminary results obtained with chiral sulfoxides provide early insights into the mechanism of these fluorination reactions.
Highly Lewis acidic fluorosulfoxonium cations can be prepared in a one‐step, chloride promoter‐free fashion from electron‐deficient sulfoxides using FXeOTf. The latter is prepared by reaction of XeF2 with TMS‐OTf, thus representing an inversion of the previously described Umpolung strategy, which failed to convert the same sulfoxides efficiently. The Lewis acidities of the obtained cations have been probed experimentally and computationally.
An efficient and general method for the preparation of achiral and chiral phosphonium salts is reported. This synthesis is based on the quaternization of phosphines and their derivatives with arynes ...generated in situ from 2-(trimethylsilyl)aryl triflates. This methodology is successfully applied to the synthesis of new valuable P-stereogenic phosphonium triflates.
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