Formation of N-sulfonylamidines by copper-catalyzed coupling of sulfonyl azides, terminal alkynes, and trialkylamines
TL;DR: In this paper, a copper-catalyzed synthesis of N-sulfonylamidines via three-component coupling of sulfonyl azides, terminal alkynes, and trialkylamines is reported.
About: This article is published in Tetrahedron Letters.The article was published on 2011-02-09. It has received 30 citations till now. The article focuses on the topics: Sulfonyl.
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TL;DR: The review of several practical and versatile approaches to ketenimine chemistry and the discovery of a variety of highly efficient reactions are presented here.
Abstract: Ketenimines are an important class of reactive species and useful synthetic intermediates. During the last two decades several practical and versatile approaches to ketenimines have been developed, leading to exhaustive investigations on ketenimine chemistry and the discovery of a variety of highly efficient reactions. Five types of reactions for ketenimines have been reported, including nucleophilic additions (ketenimines can be used as both electrophiles and nucleophiles), radical additions, cycloaddition reactions, electrocyclic ring closure reactions, and σ rearrangements. Furthermore, numerous complex organic compounds, particularly the biologically interesting heterocycles, have been constructed using these methodologies. The review of these accomplishments is presented here.
207 citations
TL;DR: A detailed study of amidine synthesis from N-allyl-N-sulfonyl ynamides is described here, and another set of tandem sigmatropic rearrangements are uncovered, leading to vinyl imidate formation.
Abstract: A detailed study of amidine synthesis from N-allyl-N-sulfonyl ynamides is described here. Mechanistically, this is a fascinating reaction consisting of diverging pathways that could lead to deallylation or allyl transfer depending upon the oxidation state of palladium catalysts, the nucleophilicity of amines, and the nature of the ligands. It essentially constitutes a Pd(0)-catalyzed aza-Claisen rearrangement of N-allyl ynamides, which can also be accomplished thermally. An observation of N-to-C 1,3-sulfonyl shift was made when examining these aza-Claisen rearrangements thermally. This represents a useful approach to nitrile synthesis. While attempts to render this 1,3-sulfonyl shift stereoselective failed, we uncovered another set of tandem sigmatropic rearrangements, leading to vinyl imidate formation. Collectively, this work showcases the rich array of chemistry one can discover using these ynamides.
73 citations
TL;DR: A comprehensive review of the evolution and growing importance of this merge of two vibrant concepts in modern organic synthesis can be found in this article, where the authors provide a comprehensive examination of selected works that highlight the evolution of the merge of sustainable metal catalysis and C H activation.
72 citations
TL;DR: Preliminary studies suggest that the reaction pathway involves initial oxidative coupling of the terminal alkyne with the secondary amine, followed by hydroamidation of the ynamine intermediate with the sulfonamide.
Abstract: Cu-catalyzed aerobic oxidative three-component coupling of a terminal alkyne, secondary amine, and sulfonamide enables efficient synthesis of amidines. The use of Cu(OTf)2 (5 mol %) produces amidines selectively without Glaser–Hay alkyne homocoupling products. Preliminary studies suggest that the reaction pathway involves initial oxidative coupling of the terminal alkyne with the secondary amine, followed by hydroamidation of the ynamine intermediate with the sulfonamide.
50 citations
TL;DR: A novel and efficient one-pot method for the synthesis of cyclopropane-fused bicyclic amidines on the basis of a CuBr2 -mediated oxidative cyclization of carbanions that provides straightforward access to biologically active and pharmaceutically important 3-azabicyclo[n.1.0]alkane frameworks under mild conditions.
Abstract: A novel and efficient one-pot method has been developed for the synthesis of cyclopropane-fused bicyclic amidines on the basis of a CuBr2 -mediated oxidative cyclization of carbanions. The usefulness of this unique multicomponent strategy has been demonstrated by the use of a wide variety of substrates to furnish novel cyclopropane-containing amidines with a quaternary center in very good yields. This ketenimine-based approach provides straightforward access to biologically active and pharmaceutically important 3-azabicyclo[n.1.0]alkane frameworks under mild conditions. The synthetic power of this methodology is exemplified in the concise synthesis of the pharmaceutically important antidepressant drug candidate GSK1360707 and key intermediates for the synthesis of amitifadine, bicifadine, and narlaprevir.
34 citations
References
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TL;DR: The basis for the unique properties and rate enhancement for triazole formation under Cu(1) catalysis should be found in the high ∆G of the reaction in combination with the low character of polarity of the dipole of the noncatalyzed thermal reaction, which leads to a considerable activation barrier.
Abstract: The Huisgen 1,3-dipolar cycloaddition reaction of organic azides and alkynes has gained considerable attention in recent years due to the introduction in 2001 of Cu(1) catalysis by Tornoe and Meldal, leading to a major improvement in both rate and regioselectivity of the reaction, as realized independently by the Meldal and the Sharpless laboratories. The great success of the Cu(1) catalyzed reaction is rooted in the fact that it is a virtually quantitative, very robust, insensitive, general, and orthogonal ligation reaction, suitable for even biomolecular ligation and in vivo tagging or as a polymerization reaction for synthesis of long linear polymers. The triazole formed is essentially chemically inert to reactive conditions, e.g. oxidation, reduction, and hydrolysis, and has an intermediate polarity with a dipolar moment of ∼5 D. The basis for the unique properties and rate enhancement for triazole formation under Cu(1) catalysis should be found in the high ∆G of the reaction in combination with the low character of polarity of the dipole of the noncatalyzed thermal reaction, which leads to a considerable activation barrier. In order to understand the reaction in detail, it therefore seems important to spend a moment to consider the structural and mechanistic aspects of the catalysis. The reaction is quite insensitive to reaction conditions as long as Cu(1) is present and may be performed in an aqueous or organic environment both in solution and on solid support.
3,855 citations
TL;DR: In this article, a review of metal-metal bridging with the presence of the amidino group is presented, with a focus on bridging modes for the group and a reference to other aza-allyl systems.
631 citations
Book•
01 Jan 1975
TL;DR: Alfassi catalysis by amidines, P.Pihiaja synthesis of amidines as mentioned in this paper, G.Boyd imidates, D.Nielson synthesis, chemistry and uses of guanidine derivatives, K.Jaworski and M.Kalinowski.
Abstract: General and theoretical aspects, G.Hafelinger structural chemistry, T.M.Krygowski and K.Wozniak stereochemical aspects of amidines, imidates and related derivatives, C.L.Perrin analysis, J.Oszczapowicz and I.Oszczapowicz mass spectra, S.Fornarini thermochemistry, K.Pihiaja synthesis of amidines, G.Boyd synthetic uses of amidines and related compounds, G.Boyd imidates, D.G.Nielson synthesis, chemistry and uses of guanidine derivatives, K.Akiba rearrangements, V.Minkin and I.E.Mikhailov tautomerism, H-bonding and basicity, J.Oszczapowicz directing and activating effects, J.Shorter biochemistry, pharmacology and toxicology of amidines and related compounds, R.J.Grout isotopically substituted amidines, P.J.Smith photochemistry and radiation chemistry of amidines and related compounds, Z.B.Alfassi catalysis by amidines, P.N.Ahlberg electrochemistry, J.Jaworski and M.Kalinowski.
410 citations
TL;DR: Two plausible mechanistic pathways involving ketenimine or triazole intermediate are tentatively presented for the copper-catalyzed three-component coupling reactions.
Abstract: A highly efficient, mild, practical, and catalytic multicomponent reaction for the synthesis of N-sulfonylamidines has been developed. This reaction has an extremely wide scope with regard to all three coupling components of alkyne, sulfonyl azide, and amine. Two plausible mechanistic pathways involving ketenimine or triazole intermediate are tentatively presented for the copper-catalyzed three-component coupling reactions.
384 citations
TL;DR: It is shown for the first time that N-sulfonyl amides can be efficiently prepared by an unconventional approach of the hydrative reaction between terminal alkynes, sulfonyl azides, and water in the presence of copper catalyst and amine base under very mild conditions.
Abstract: It is shown for the first time that N-sulfonyl amides can be efficiently prepared by an unconventional approach of the hydrative reaction between terminal alkynes, sulfonyl azides, and water in the presence of copper catalyst and amine base under very mild conditions. The present route is quite general, and a wide range of alkynes and sulfonyl azides are readily coupled catalytically with water to furnish amides in high yields. A variety of labile functional groups are tolerated under the conditions, and the reaction is regioselective in that only terminal alkynes react while double or internal triple bonds are intact. The reaction can be readily scaled up and is also adaptable to a solid-phase procedure with high efficiency.
379 citations