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We report here a formal insertion of a metal carbene complex in a single carbon‐carbon bond. This behavior occurs with the participation of an α‐imino gold carbene complex, generated from benzofused triazapentalenes or, in a one‐pot procedure, from their 1‐propargyl‐1H‐benzotriazole precursors, and gold‐catalytically activated ynamides. As the result, 3H‐indole derivatives were obtained, with formation of a quaternary center. A computational analysis carried out on the reaction mechanism indicates that the bulkiness of the gold ligand plays a key role forcing a conformation, which includes aromatic interactions, that favors the approximation of the carbenic carbon to the reactive site. In addition, a negative crossover experiment rules out a cationic arene migration pathway. [ABSTRACT FROM AUTHOR]

A triphenylphosphine‐ligated cobalt‐catalyzed cyclization manifold with various 1,3‐dicarbonyl compounds and halogenated N‐allyl ynamides was accomplished under alkaline reaction conditions, facilitating the synthesis of differently sized N‐heterocycles. A large array of products was prepared to demonstrate the selective synthesis of N‐heterocycles of different ring sizes (5‐, 6‐, and 7‐membered rings) via cobalt catalysis. The reaction has broad substrate scope and a wide range of functional groups. [ABSTRACT FROM AUTHOR]

In recent years, asymmetric catalysis of ynamides has attracted much attention, but these reactions mostly constructed central chirality, except for a few examples on the synthesis of axially chiral compounds which exclusively relied on noble‐metal catalysis. Herein, a facile access to axially chiral N‐heterocycles enabled by chiral Brønsted acid‐catalyzed 5‐endo‐dig cyclization of ynamides is disclosed, which represents the first metal‐free protocol for the construction of axially chiral compounds from ynamides. This method allows the practical and atom‐economical synthesis of valuable N‐arylindoles in excellent yields with generally excellent enantioselectivities. Moreover, organocatalysts and ligands based on such axially chiral N‐arylindole skeletons are demonstrated to be applicable to asymmetric catalysis. [ABSTRACT FROM AUTHOR]

In recent years, asymmetric catalysis of ynamides has attracted much attention, but these reactions mostly constructed central chirality, except for a few examples on the synthesis of axially chiral compounds which exclusively relied on noble‐metal catalysis. Herein, a facile access to axially chiral N‐heterocycles enabled by chiral Brønsted acid‐catalyzed 5‐endo‐dig cyclization of ynamides is disclosed, which represents the first metal‐free protocol for the construction of axially chiral compounds from ynamides. This method allows the practical and atom‐economical synthesis of valuable N‐arylindoles in excellent yields with generally excellent enantioselectivities. Moreover, organocatalysts and ligands based on such axially chiral N‐arylindole skeletons are demonstrated to be applicable to asymmetric catalysis. [ABSTRACT FROM AUTHOR]

Demonstrated herein is a keteniminium triggered dienone‐phenol rearrangement of yne‐dienone and a regioselective intramolecular 6‐endo‐dig cyclization of aryl‐propargyl ether cascade for the synthesis of 2H‐chromene bearing ketene‐N,O‐acetals. The gold‐catalyst and ynamide combination forms a keteniminium species in situ and makes the dienone‐phenol rearrangement viable with 1,2‐migration of common alkyl substituents (methyl and ethyl) and phenyl group. The transformation tolerates common functional groups and N‐sulfonyl protecting groups in ynamides exhibiting broad scope. The transformation proceeds through intramolecular proton transfer to the vinylic gold species; deuterium scrambling study supports this observation. [ABSTRACT FROM AUTHOR]

Research on the synthesis of heterocyclic scaffolds is an important challenge in organic synthesis because heterocycles are an important block in the structure of many drugs and pharmaceutical molecules. Ynamides are one the most versatile and enabling building blocks in organic synthesis because they have recently used starting materials for the construction of multifunctional compounds especially heterocyclic compounds. In recent times, a number of catalytic systems have been reported in the literature for the synthesis of heterocyclic scaffolds from ynamide derivatives. This review has outlined the extensive application of ynamide derivatives in the synthesis of a library of heterocyclic scaffolds. Based on Ynamides: catalysis in the synthesis of heterocyclic scaffolds [ABSTRACT FROM AUTHOR]

Ynamides are unique alkynes with a carbon–carbon triple bond directly attached to the nitrogen atom bearing an electron-withdrawing group. The alkyne is strongly polarized by the electron-donating nitrogen atom, but its high reactivity can be finely tempered by the electron-withdrawing group. Accordingly, ynamides are endowed with both nucleophilic and electrophilic properties and their chemistry has been an active research field. The catalytic intermolecular annulations of ynamides, featuring divergent assembly of structurally important amino-heterocycles in a regioselective manner, have gained much attention over the past decade. This review aims to provide a comprehensive summary of the advances achieved in this area involving transition metal and acid catalysis. Moreover, the intermolecular annulations of ynamide analogs including ynol ethers and thioalkynes are also discussed, which can provide insights into the reactivity difference caused by the heteroatoms. [ABSTRACT FROM AUTHOR]

In this review we present the transformations that have been developed with ynamides and free radicals. These reactions involve carbon‐, heteroatom‐ or even metalloid‐centered radicals and include inter‐ and intra‐molecular reactions. The scope and mechanism of these transformations are discussed in details, including the most recent examples relying on photoredox catalysis. [ABSTRACT FROM AUTHOR]

Functionalised N‐heterocyclic pyridinium N‐aminides have been designed and synthesised to evaluate a nitrenoid‐based annulation strategy into imidazole‐fused oxo‐substituted frameworks of importance to medicinal and agrochemical discovery programmes. Sulfenyl substituted ynamides were identified as privileged reactants affording productive gold‐catalysed annulation reactions with these and other nitrenoids. This annulation method provides selective and efficient access into geminally amino‐sulfenyl substituted nitrogen heterocycles under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Demonstrated herein is an AuI‐catalyzed annulation of sulfonyl‐protected ynamides with substituted 1,2‐benzisoxazoles for the synthesis of E‐benzo[e][1,3]oxazine derivatives. The transformation involves the addition of benzisoxazole to the gold‐activated ynamide, ring expansion of the benzisoxazole fragment to provide an α‐imino vinylic gold intermediate, and 1,2‐migration of the sulfonamide motif to the masked carbene center to deliver the respective ring‐expanded benzo[e][1,3]oxazine of predominant E configuration. A trapping experiment justifies the participation of the α‐imino masked gold carbene. DFT computations also support the hypothesized mechanism and rationalize the product stereoselectivity. [ABSTRACT FROM AUTHOR]

A metal-free intramolecular alkoxylation-initiated cascade cyclization of allyl ether-tethered ynamides has been developed. Various highly functionalized 3-isochromanones can be obtained in generally good to excellent yields under mild reaction conditions. Moreover, this asymmetric cyclization has also been realized via a stereocontrolled [3,3] rearrangement by employing a traceless chiral directing group. In addition, an unexpected [1,3] O-to-C rearrangement is observed in the case of the ynamide substrate bearing a phenyl-substituted alkene, which is distinctively different from the related gold catalysis. [ABSTRACT FROM AUTHOR]

A smooth, gold catalyzed, atom‐economical and regioselective synthesis of indoles is reported here. The reaction occurs from a nucleophilic attack of in situ synthesized triazapentalenes to gold activated ynamides and involves the participation of α‐imino gold carbene complexes. The use of sulfonyl ynamides drives the reaction to the formation of 2‐amidosubstituted indoles. However, the employment of 2‐oxazolidinolylynamides allows the formation of both isomers, such as, 2‐amido‐ and 3‐amidosubstituted indoles. In this case, the regioselection could be controlled by a correct choice of the catalyst ligand and the electron‐donating capability of the aryl substituent of the ynamide. A correct control in both parameters permits a totally regioselective synthesis of one or the other regioisomer. Isolation of key intermediates and X‐ray analysis allowed for a plausible explanation for this behavior. [ABSTRACT FROM AUTHOR]

A regioselective sulfonyl/sulfinyl migration cycloisomerization cascade of alkyne‐tethered ynamides is developed in the presence of XPhosgold catalyst. This reaction is the first example of a general [1,3]‐sulfonyl migration from the nitrogen center to the β‐carbon atom of ynamides, followed by umpolung 5‐endo‐dig cyclization of the ynamide α‐carbon atom to the gold‐activated alkyne, and final deaurative [1,5]‐sulfinylation. This process allows the synthesis of peripherally decorated unconventional 4‐sulfinylated pyrroles with broad scope from N‐propargyl‐tethered ynamides. In contrast, N‐homopropargyl‐tethered ynamides undergo intramolecular tetradehydro Diels–Alder reaction to provide 2,3‐dihydro‐benzo[f]indole derivatives. Control experiments and density‐functional theory studies were used to study the reaction pathways. Double migration: A regioselective umpolung [1,3]‐sulfonyl/[1,5]‐sulfinyl migration cycloisomerization cascade of alkyne‐tethered ynamides allows the construction of unconventional 4‐sulfinylated pyrroles through deaurative [1,5]‐sulfinylation. Density functional theory was used to study the reaction pathway. [ABSTRACT FROM AUTHOR]

Copper‐catalyzed amidation of alkynyl bromides can be carried out in water for the first time, which is made possible by a micellar catalysis strategy using rosin‐based surfactant APGS‐550‐M. The surfactant can be easily prepared from natural abundant biomass, resin acids. Studies as to substrate scope and reaction aqueous medium recycling showcase the ease and sustainability of this technology. The synthesis of ynamides in water was achieved by a micellar catalysis strategy using rosin‐based surfactant APGS‐550‐M, which can be easily prepared from natural abundant biomass. [ABSTRACT FROM AUTHOR]

A general and efficient procedure for the copper-catalyzed photoinduced radical domino cyclization of ynamides and cyanamides providing an efficient access to complex tri-, tetra- and pentacyclic nitrogen heterocycles is reported. Upon visible light irradiation in the presence of catalytic amounts of [(DPEphos)(bcp)Cu]PF6 and an amine, a range of unactivated aryl and alkyl iodides were shown to be smoothly transformed to the corresponding radical species, initiating the radical domino cyclization. This procedure provides a unified entry to rosettacin, luotonin A, and deoxyvasicinone that could be efficiently prepared in a limited number of steps. [ABSTRACT FROM AUTHOR]

Carbon-carbon bond cleavage/functionalization is synthetically valuable, and selective carbonyl−C(sp3) bond cleavage/alkynylation presents a new perspective in constructing ynamides, ynoates, and ynones. Reported here is the first alkoxyl-radical-enabled carbonyl−C(sp3) bond cleavage/alkynylation reaction by photoredox catalysis. The use of novel cyclic iodine(III) reagents are essential for β-carbonyl alkoxyl radical generation from β-carbonyl alcohols, including alcohols with high redox potential ( [ABSTRACT FROM AUTHOR]

We have developed a borane-catalyzed regio- and stereoselective hydrosilylation of internal ynamides for the first time. The scope of ynamide substrates and silane reactants was broad under mild reaction conditions, affording synthetically versatile β-silyl (Z)-enamide products. The observed stereoselectivity was reasoned to be due to the β-silicon effect on a postulated ketene iminium intermediate. [ABSTRACT FROM AUTHOR]

An introduction is presented which discusses various reports within the issue on topics including asymmetric catalysis, modulating protein-protein interactions, and synthesis of ynamides.

A novel and selective method for the synthesis of carbamoylacetates via the alcoholysis of 3-iodopropynamides has been developed. 3-Iodopropynamides react with alcohols in the presence of palladium( II) acetate and DABCO to afford the corresponding carbamoylacetates in moderate to good yields. [ABSTRACT FROM AUTHOR]

Copper(I)-zeolites, especially copper(I)-ultra stable Y zeolite (USY), are very efficient heterogeneous catalysts for the coupling of functionalized 1-bromoalkynes and various nitrogen derivatives. Under these conditions, sulfonylated alkyl- or arylamines and various N-heterocycles, such as oxazolidinones or indoles, could be efficiently transformed into the corresponding N-alkynyl derivatives. However, imidazoles gave addition products rather than coupling products. The reaction conditions proved compatible with a variety of functional and protecting groups. Such zeolitic catalysts can be recycled and reused at least five times without significant deactivation. Low catalyst loading could be used (4 mol%) and as low as 0.8 mol% of this heterogeneous copper catalyst still gave good conversion and yields. [ABSTRACT FROM AUTHOR]

Diynes and ynamides are important products in chemical synthesis. An efficient palladium-catalyzed homocoupling reaction of 2-bromo-1-iodoalkenes to give 1,3-diynes has been developed. The reactions are conducted under convenient conditions and provide products in moderate to excellent yields. Moreover, ynamides were synthesized from 2-bromo-1-iodoalkenes and carbamates, and it is noteworthy that this reaction is catalyzed by nanoparticulate copper(I) oxide to give ynamides in high yields. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed trans-hydroalkynylation of N-sulfonyl ynamides has been achieved for the first time, providing α-alkynylation adducts in high yields with excellent regio- and stereoselectivity. The resulting enyne products can serve as the useful precursors for the elaboration of naphthalene derivatives via a platinum-catalyzed cycloisomerization reaction. [ABSTRACT FROM AUTHOR]

Abstract: A study concerning the gold(I)-catalyzed transformation of N-(hex-5-enynyl) tert-butyloxycarbamates is described. The mild conditions employed allow the moderately efficient but stereoselective synthesis of a range of bicyclic carbamates following a formal [4+2] cycloaddition process. [Copyright &y& Elsevier]

Gold-catalyzed 1,2-iminonitronation of propiolate derivatives with nitrosoarenes to give α-imidoyl nitrones is described; this new reaction is applicable to diverse propiolate derivatives and nitrosoarenes. [ABSTRACT FROM AUTHOR]

• Dihydro-[1,3]oxazino[4,3-a] isoindole and tetrahydroisoquinoline skeletons. • Addition-cyclization of ynamides with N -acyliminium ions. • Cu(OTf) 2 catalyzed this transformation effectively. An efficient approach to access functionalized dihydro-[1,3]oxazino[4,3-a] isoindole and tetrahydroisoquinoline skeletons has been developed through the addition-cyclization process of ynamides 8 with N -acyliminium ions generated from N,O -acetals 6,7. The reactions were conducted under the catalysis of Cu(OTf) 2 , and a number of functionalized dihydro-[1,3]oxazino[4,3-a] isoindoles 9a-9y and tetrahydroisoquinolines 10a-10g, 11a-11p were generated in 48–98% yields. When chiral ynamides 8n-8u were used, optically pure products 11a-11p could be obtained with good to excellent yields and diastereoselectivities. [ABSTRACT FROM AUTHOR]

The title reaction of ynamides of type (I), (IV), and (VI) with benzylic azides (II) offers a highly regioselective access to 2-aminoindoles (III) and (V). Indolylmethyl derived azides (VI) and (IX) give 3-amino-β-carbolines. [ABSTRACT FROM AUTHOR]

An abstract of the article "TfOH-Mediated [2 + 2 + 2] Cycloadditions of Ynamides with Two Discrete Nitriles: Synthesis of 4-Aminopyrimidine Derivatives" by P. Chen and colleagues is presented.

An unprecedented gold(I)-induced β-site regioselective formal [3 + 2] cycloaddition of ynamides with pyrido[1,2-b]indazoles is reported, giving the title compounds in good to excellent yields. [ABSTRACT FROM AUTHOR]

A novel zinc-catalyzed oxidative reaction of ynamides with phenols, thiophenols, and anilines allows the access to various α-substituted amides. [ABSTRACT FROM AUTHOR]

A cyclization reaction of 2-iodobenzoic acids and ynamides gives sulfonamido-isocoumarins with excellent regioselectivities and various functional groups are tolerated. [ABSTRACT FROM AUTHOR]

Copper(I)- or silver(I)-catalyzed trans-hydrofluorination of ynamides is achieved for the first time. [ABSTRACT FROM AUTHOR]

The efficient procedure provides diverse 4-fluoro-2-en-1-amides with high (E)-stereoselectivity. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "Sulfonamide-Directed Gold-Catalyzed [2 + 2 + 2]-Cycloadditions of Nitriles with Two Discrete Ynamides to Construct 2,4-Diaminopyridine Cores" by Yu-Ling Chen and others, published in the "Chemical Communications" in 2016.

The reaction N-allyl ynamides in the presence of Au(picolinate)Cl2 gives polycyclic heterocycles. [ABSTRACT FROM AUTHOR]

An abstract of the study "Cu-Catalyzed Alkylative Carboxylation of Ynamides with Dialkylzinc Reagents and Carbon Dioxide" by M. Takimoto and colleagues is presented.

A diagram is presented which shows the nucleophilic substitution (N-substitution) dependent stereoselectivity switch in palladium catalyzed ynamide hydroalkynylation.

An abstract of the article "Facile and Efficient Synthesis of [1,4]Oxazino[3,2-b]indoles and 1H-Pyrazino[2,3-b]indoles Through Gold-Catalyzed Cascade Cyclization of (Azido)Ynamides," by C.-H. Chen and colleagues is presented.

An abstract of the article "Diversity in Gold-Catalyzed Formal Cycloadditions of Ynamides with Azido-alkenes or 2H-Azirines: [3 + 2] versus [4 + 3] Cycloadditions" by S. K. Pawar and colleagues is presented.

The entitled hydroboration of ynamides using bis(pinacolato)diboron as the borylating reagent, affords (E)-β-alkenylamide boronates in good yields with excellent regio- and stereoselectivity. [ABSTRACT FROM AUTHOR]

The thermally driven [2 + 2] cycloaddition of substrates (I) and (IV) represents the first examples of an intramolecular Ficini reaction. [ABSTRACT FROM AUTHOR]

Palladium-Catalyzed Intramolecular Cyclization of Ynamides: Synthesis of 4-Halo-oxazolones are presented.

The asymmetric [2 + 2] cycloaddition of cyclic α-alkylidene β-oxo imides (I), (IV), and (VI) with ynamides (II) is reported. [ABSTRACT FROM AUTHOR]

A gold-catalyzed cycloisomerization of 1,6-diynes containing an ynamide propargyl ester or carbonate moiety is developed that provides an attractive route to diverse-substituted 3-acyloxy-1,4-dihydrocyclopenta[b]indoles. [ABSTRACT FROM AUTHOR]

The reaction tolerates aryl and alkyl substituted substrates. [ABSTRACT FROM AUTHOR]

Copper(I)-ultra stable Y zeolite (USY) is found to be a very efficient heterogeneous catalyst for coupling of functionalized 1-bromoalkynes and various nitrogen derivatives. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "Palladium-Catalyzed Addition of 1,3-Diones to Ynamides: An Entry to Alkoxy-Substituted Enamides" by L. V. Graux and others, published in the periodical "ChemCatChem" in 2014.

An abstract of the article "Gold- and Silver-Catalyzed [4 + 2] Cycloadditions of Ynamides with Oxetanes and Azetidines" by S. K. Pawar and colleagues is presented.

A new method to synthesize dihydroisoquinolines is reported which relies on a gold-catalyzed formal [4 + 2] cycloaddition between ynamides and imines. [ABSTRACT FROM AUTHOR]

A diagram is presented which explains the chemical structure of sulfur-ylides formation sequence and intramolecular oxidation of Ynamides.