The fully regio‐ and stereoselective Zn‐catalyzed hydrocyanation of ynamides is reported and represents a general access to various trisubstituted E‐α‐enamidonitriles. The catalyst‐free ...photoisomerization selectively yields the energetically comparable Z‐stereoisomer. Finally, the synthetic potential of these new α‐enamidonitriles was evaluated through the synthesis of original heterocycles.
Trisubstituted E‐2‐amidoacrylonitriles are produced by direct hydrocyanation of ynamides. Z isomers can be obtained selectively using a thermo‐neutral catalyst‐free photoisomerization.
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.
The palladium‐catalyzed silylcyanation of ynamides is described. This reaction is fully regioselective, delivering tetrasubstituted 2‐aminoacrylonitriles derivatives exclusively. Unexpectedly, the ...nature (aryl or alkyl) of the substituent located at the β‐position of the ynamide directly controls the stereoselectivity. The reaction tolerates a number of functional groups and can be considered as the first general access to fully substituted 2‐aminoacrylonitriles. Given the singular reactivity observed, a computational study was performed to shed light on the mechanism of this intriguing transformation. Relying on the specific reactivity of the newly installed vinylsilane functionality, the scope of 2‐aminoacrylonitriles has been enlarged by postfunctionalization.
Tetrasubstituted 2‐aminoacrylonitriles (α‐enaminonitriles) are underinvestigated building blocks due to the lack of methodologies to synthesize them in a controlled manner. A general access to these valuable scaffolds accompanied by mechanistic investigations and DFT calculations is described. This highly regio‐ and stereoselective strategy relies on the use of the first intermolecular silylcyanation of ynamides.
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.
Owing to the high interest in the OCF3 group for pharmaceutical and agrochemical applications, trifluoromethoxylation received great attention in the last years with several new methods for this ...approach towards OCF3‐comprising compounds. Yet, it most often requires the beforehand preparation of specific F3CO− transfer reagents, which can be toxic, expensive, unstable, and/or generate undesired side‐products upon consumption. To circumvent this, the in‐situ generation of gaseous fluorophosgene from triphosgene, its conversion by fluoride into the OCF3 anion, and the direct use of the latter in nucleophilic substitutions is an appealing strategy, which, although recently approached, has not been fully exploited. We disclose herein our efforts towards this aim.
An efficient atom economical trifluoromethoxylation method was developed with no need for trifluoromethoxylation reagent. This method relies on the in‐situ generation of fluorophosgene and its conversion into OCF3 anion to achieve nucleophilic substitution on a series of alkyl iodides.
Morgan Donnard Donnard, Morgan
Angewandte Chemie International Edition,
March 28, 2022, Letnik:
61, Številka:
14
Journal Article
Recenzirano
Odprti dostop
“My favorite science outreach activity is meeting with young people at science fairs to answer the questions they have about the world around them (not always easy to answer but often inspiring) … I ...chose chemistry as a career because you transform and model matter at the scale of the molecule, a scale imperceptible to human beings until very recently in our history. …” Find out more about Morgan Donnard in his Introducing … Profile.
Sulfuryl fluoride is a gas produced on a multi‐ton scale for its use as a fumigant. In the last decades, it has gained interest in organic synthesis as a reagent with unique properties in terms of ...stability and reactivity when compared to other sulfur‐based reagents. Sulfuryl fluoride has not only been used for sulfur‐fluoride exchange (SuFEx) chemistry but also encountered applications in classic organic synthesis as an efficient activator of both alcohols and phenols, forming a triflate surrogate, namely a fluorosulfonate. A long‐standing industrial collaboration in our research group drove our work on the sulfuryl fluoride‐mediated transformations that will be highlighted below. We will first describe recent works on metal‐catalyzed transformations from aryl fluorosulfonates while emphasizing the one‐pot processes from phenol derivatives. In a second section, nucleophilic substitution reactions on polyfluoroalkyl alcohols will be discussed and the value of polyfluoroalkyl fluorosulfonates in comparison to alternative triflate and halide reagents will be brought to light.
Nickel(0) nanoparticles coordinated to NHC ligands bearing N-coordinated cinnamyl moieties were readily prepared by reduction of a NiCpBr(NHC-cinnamyl) complex with methyl magnesium bromide. The ...combination of a strong σ-donor NHC ligand with a π-coordinating appended cinnamyl moiety likely prevents nickel(0) nanoparticle aggregation to larger inactive species, and allows the effective and (
Z
)-selective semi-hydrogenation of alkynes and ynamides
.
Nickel(0)-NHC nanoparticles bearing cinnamyl moieties catalyse effectively (
Z
)-selective semi-hydrogenations.
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