By one-pot four- and three-component Ugi reactions involving convertible isocyanides and unexplored pyrrole-containing β-chlorovinylaldehyde, a small library of 20 bisamides with unusual behavior in post-Ugi transformations was prepared and characterized. Surprisingly, a well-documented approach to obtain peptide-containing carboxylic acids through acid hydrolysis of the convertible isocyanide moiety in the Ugi bisamides proceeded in an unexpected manner in our case, leading to the formation of derivatives of amides of heterylidenepyruvic acid. An optimized synthetic protocol for this transformation was elaborated and a plausible sequence involving the elimination of the 2-chloroacetamide moiety and the conversion of the β-chlorovinyl fragment into a vinyl one is provided.
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http://dx.doi.org/10.3762/bjoc.20.156 | DOI Listing |
Org Biomol Chem
October 2024
Institute of Chemistry, Saint Petersburg State University, Saint Petersburg 199034, Russia.
Structurally diverse pyrroles, indoles and imidazoles bearing an -ω-azidoalkyl moiety and an aldehyde or ketone function were prepared and successfully introduced into imine generation the intramolecular Staudinger/aza-Wittig tandem reaction. Reduction of the generated imines led to medicinally relevant nitrogen-containing fused heterocycles such as tetrahydropyrrolo[1,2-]pyrazines and diazepines. Rare 8-membered hexahydropyrrolo[1,2-][1,4]diazocine and 9-membered dihydro-4,8-(metheno)pyrrolo[1,2-][1,4]diazacycloundecine were also synthesized.
View Article and Find Full Text PDFBeilstein J Org Chem
July 2024
Institute of Functional Materials Chemistry, State Scientific Institution "Institute for Single Crystals" of National Academy of Sciences of Ukraine, Nauky Ave., 60, 61072, Kharkiv, Ukraine.
By one-pot four- and three-component Ugi reactions involving convertible isocyanides and unexplored pyrrole-containing β-chlorovinylaldehyde, a small library of 20 bisamides with unusual behavior in post-Ugi transformations was prepared and characterized. Surprisingly, a well-documented approach to obtain peptide-containing carboxylic acids through acid hydrolysis of the convertible isocyanide moiety in the Ugi bisamides proceeded in an unexpected manner in our case, leading to the formation of derivatives of amides of heterylidenepyruvic acid. An optimized synthetic protocol for this transformation was elaborated and a plausible sequence involving the elimination of the 2-chloroacetamide moiety and the conversion of the β-chlorovinyl fragment into a vinyl one is provided.
View Article and Find Full Text PDFRSC Adv
June 2024
Medical Analysis Department, Applied Science Faculty, Tishk International University Erbil Kurdistan Region Iraq
A Cu-catalyzed tandem transformation of Ugi adducts through CH/NH bond functionalization reactions was reported for synthesizing a broad spectrum of indolo/pyrrolo-[1,2-]quinoxaline-6/4-carboxamide, 7-indolo[2,3-]quinoline-6-carboxamide, and 1-(cyclohexylamino)-14-indolo[2,3-][1,4]oxazino[4,3-]quinolin-4(3)-one derivatives in moderate to excellent yields. In this protocol the Ugi condensation of aromatic aldehydes, anilines, acids, and isocyanides leads to the formation of bis-amides in methanol at room temperature. This approach employed simple reaction conditions, including Ugi product as starting material, CuI, l-proline as a ligand, and cesium carbonate, in DMSO for 8 h.
View Article and Find Full Text PDFOrg Biomol Chem
February 2024
Institute of Chemistry, Saint Petersburg State University, Saint Petersburg 199034, Russia.
A series of structurally diverse α-heteroatom substituted methyl azides (XCHN, where X = phthalimidoyl, benzotriazolyl, arylsulfanyl, aryloxy, alkoxy) have been prepared and evaluated for the generation of imines the Staudinger/aza-Wittig tandem reaction with aldehydes and triphenylphosphine. The obtained imines were successfully introduced into four types of multicomponent reactions: the Staudinger β-lactam synthesis with diazo carbonyl compounds, the Castagnoli-Cushman reaction with cyclic anhydrides, and the Ugi and azido-Ugi reactions with isocyanides and carboxylic acids or TMS-azides. These transformations allowed the preparation of four-to-seven-membered lactams, acyclic bisamides and 5-(aminomethyl)-1-alkyltetrazoles with a complex and previously poorly accessible periphery.
View Article and Find Full Text PDFJ Org Chem
October 2023
Department of Chemistry, Mohanlal Sukhadia University, Udaipur 313001, India.
The combination of the Ugi reaction and electro-organic synthesis can aid in the creation of novel heterocycles that have not been previously explored. In this study, a new strategy utilizing bis-amides from the Ugi reaction has been developed, which can produce C-S, C-Se, and C-C═O functionalized five-membered spirolactams mediated by electricity under catalyst- and metal-free conditions. Notably, this approach can be applied using a microelectro-flow reactor (μ-EFR) for gram-scale synthesis.
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