Search

Inexpensive cobalt‐catalyzed, pivalic acid‐assisted oxidative C−H functionalization of benzimidates or NH‐benzaldimines with ynamides is presented, providing an access to 3‐aminoisoquinoline derivatives. The procedure is compatible with various substrates featuring alkyl, alkoxy, acyl or halogen as substituents, heteroaryl structures, and diverse ynamides. The reaction has been scaled up, with subsequent transformation of the yielded products. Control experiments and mechanistic investigations corroborate the regioselectivity of this conversion, positioning the amine group proximal to the nitrogen atom in isoquinolines. [ABSTRACT FROM AUTHOR]

In this manuscript we report the synthesis of 3‐amido‐benzo[b]silines thanks to a 2‐step strategy involving a 3‐component silylformylation of ynamides followed by a Friedel‐Crafts cyclization/isomerizing dehydration domino sequence. This reaction is tolerant to various structural variations and has allowed us to synthesize a library of diversely substituted silacycles with yields from 33 to 85%. We also studied the fluorescence properties of these compounds which show structural similarities with recognized probes such as Si‐Rhodamine for example. [ABSTRACT FROM AUTHOR]

Synthesis of bicyclic scaffolds has gained significant attention in drug discovery due to their potential to mimic benzene bioisosteres. Here, we present a mild and scalable Sc(OTf)3‐catalyzed [3+2] cycloaddition of bicyclo[1.1.0]butanes (BCBs) with ynamides, yielding a diverse array of polysubstituted 2‐amino‐bicyclo[2.1.1]hexenes in good to excellent yields. These products offer valuable starting materials for the construction of novel functionalized bicyclo[1.1.0]butanes. Preliminary mechanistic studies indicate that the reaction involves a nucleophilic addition of ynamides to bicyclo[1.1.0]butanes, followed by an intramolecular cyclization of in situ generated enolate and keteniminium ion. We expect that these findings will encourage utilization of complex bioisosteres and foster further investigation into BCB‐based cycloaddition chemistry. [ABSTRACT FROM AUTHOR]

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]

This article discusses the synthesis of ynamides, a class of N-alkynyl compounds, through various catalytic reactions. The authors highlight the importance of ynamides in the synthesis of nitrogen-containing scaffolds and summarize existing methods for their synthesis. They also present their own research on the direct catalytic addition of terminal alkynes to azodicarboxylates to produce ynehydrazides, which can then be converted into ynamides. The authors propose potential future directions for further research in this field. [Extracted from the article]

[Display omitted] An In(OTf) 3 -catalyzed oxygenative bifunctionalization reaction has been developed for the facile synthesis of various α-functionalized ketones. A wide range of aryl sulfoxides and electron-rich arylalkynes prove to be suitable substrates for this transformation. The potential of our method was then extended to the synthesis of 8-substituted quinolines from ynamides and quinoline- N -oxides. [ABSTRACT FROM AUTHOR]

[Display omitted] A divergent transformation of ynamides with anthranils has been reported, which leads to the synthesis of various 7-acylindoles and 2-aminoquinolines in moderate to excellent yields. Indium(III) triflate is used as a cheap and readily available catalyst and the method exhibits high functional group tolerance. [ABSTRACT FROM AUTHOR]

[Display omitted] A simple HNTf 2 /DMSO system has been developed for the intermolecular oxgenative bifunctionalization of ynamides to produce various α -functionalized amides, where DMSO functions both as the oxygen donor and the solvent. Scope study shows that electron-rich ynamides and nucleophiles such as alcohols, thiols and electron-rich arenes are suitable reaction partners in this transformation. [ABSTRACT FROM AUTHOR]