Synthesis of α‐Isocyano‐α‐alkyl(aryl)acetamides and Their Use in the Multicomponent Synthesis of 5‐Aminooxazole, Pyrrolo[3,4‐b]pyridin‐5‐one and 4,5,6,7‐Tetrahydrofuro[2,3‐c]pyridine.

Abstract

Oxazine derivatives R 0595Synthesis of α-Isocyano-α-alkyl (aryl)acetamides and Their Use in the Multicomponent Synthesis of 5-Aminooxazole, Pyrrolo[3,4-b]pyridin-5-one and 4,5,6,7-Tetrahydrofuro[2,3-c]pyridine. -With the isonitrile (V) in hand, novel multicomponent reactions to prepare 5-aminooxazoles, pyrrolopyridinones, and tetrahydrofuropyridines are developed. -(FAYOL, A.; HOUSSEMAN, C.; SUN, X.; JANVIER, P.; BIENAYME, H.; ZHU*, J.; Synthesis 2005, 1, 161-165; Inst. Chim. Subst. Nat., CNRS, F-91198 Gif-sur-Yvette, Fr.; Eng.) -Jannicke 20-161

Synthesis of Polyheterocyclic Pyrrolo[3,4-b]pyridin-5-ones via a One-Pot (Ugi-3CR/aza Diels-Alder/N-acylation/aromatization/SN2) Process. A Suitable Alternative towards Novel Aza-Analogues of Falipamil

“…Then, 1.2 equiv. of the isocyanide 8a (prepared in three steps from the racemic phenylalanine [21]) were added sequentially to provide the corresponding 5-aminooxazoles 9a – i in quantitative yields. These intermediates used as in situ were prepared to access to the polyheterocycles 11a – i in one-pot manner.…”

Isoselenocyanates derived from amino acid esters: an expedient synthesis and application to the assembly of selenoureidopeptidomimetics, unsymmetrical Selenoureas and selenohydantoins

“…Unlike esters and α‐isocyano carboxamides are stable solids and odorless but retain the isocyanide reactivity in isocyanide based multicomponent reactions (IMCRs)47, 48. Four complementary protocols are available to access this important starting material48, 49. To implement our other objective in making α‐isoselenocyanato carboxamides 5 (Figure 3), six known α‐isocyano carboxamides were made employing known procedure.…”

Synthesis of bis-furyl-pyrrolo[3,4-b]pyridin-5-ones via Ugi–Zhu reaction and in vitro activity assays against human SARS-CoV-2 and in silico studies on its main proteins

“…First, it was necessary to synthesize the α-isocyanoacetamides 6a-b in three reaction steps according to the Zhu and Bienaymé protocol starting from their corresponding amino acids phenylalanine and tyrosine, respectively. 25 Once achieved them, according to the UZ-3CR mechanism, a condensation occurs between aldehydes 2a-b and amines 3a-b to access to imines 4a-f, which become in Lewis' iminium-like cations 5a-f after reacting with catalytic amounts of ytterbium(III) triflate. Then, an α-nucleophilic attack by the isocyanides 6a-b to 5a-f afforded the 5-aminooxazoles 8a-f via a non-prototropic chain-ring tautomerization of 7a-f. Then, after addition of maleic anhydride (9), an aza-Diels-Alder cycloaddition followed by a N-acylation/decarboxylation/dehydration 26 took place under a cascade-type one pot process towards the corresponding bisfuryl-pyrrolo [3,4-b]pyridin-5-ones 1a-f in 45 to 82% overall yields (Scheme 1).…”