A Domino Reaction of α,β-Acetylenic γ-Hydroxy Nitriles with Arenecarboxylic Acids: An Unexpected Facile Shortcut to 4-Cyano-3(2H)-furanones

Abstract

An unexpected facile domino reaction of alpha,beta-acetylenic gamma-hydroxy nitriles with arenecarboxylic acids (Et(3)N, MeCN, 20-25 degrees C, 48 h) affords 4-cyano-3(2H)-furanones in 67-86% yield. The reaction is triggered by the addition of an arenecarboxylic acid to a triple bond, followed by the domino reaction sequence: intramolecular transesterification-enol formation and Claisen condensation of the ketoacetonitrile tautomer with ester functional group.

Synthesis of Substituted 3(2H)-Furanones Using Alkylative Intramolecular Cyclization of Sulfonium Salts

“…Sulfonium salts 1 bearing isopropyl, cyclopentyl, and cyclohexyl esters gave the corresponding 5-alkoxy-3(2H)-furanones 2 in high yields (entries 9-11). Similarly, 3(2H)-furanones with allyloxy, propargyloxy, phenyloxy, benzyloxy, or 4-bromobenzyloxy groups in the 5 position were obtained in high yields from the corresponding sulfonium salts (entries [12][13][14][15][16]. It is noteworthy that the efficient construction of 3(2H)-furanone with a variety of alkoxy groups was accomplished within 1-5 h in good yields in all cases.…”

“…Among the examined solvents, the use of THF resulted in the best yield (entries 1 and 6-8). Having defined the optimized conditions, we next examined the scope and limitations of ester part of sulfonium salts 1 (entries [9][10][11][12][13][14][15][16]. Toward the substrate scope, all sulfonium salts 1b-1i were prepared by the reaction of corresponding 4-bromoacetoacetates with diphenylsulfide in the presence of silver (I) tetrafluoroborate.…”

Peculiarities of the tandem reaction between cyanoacetylenic alcohols and aminobenzoic acids: Synthesis of 5,5-dialkyl-2-(3-aminophenyl)-4-oxo-4,5-dihydrofuran-3-carbonitriles

“…1f Recently, we have briefly reported a novel general methodology for the synthesis of 5,5-dialkyl-2-aryl-4-oxo-4,5-dihydrofuran-3-carbonitriles by the tandem reaction between cyanoacetylenic alcohols and substituted benzoic acids (Scheme 1). 8 Despite the large suite of substituted benzoic acids applied to this reaction, aminobenzoic acids have not been used, because when these were treated with cyanoacetylenic alcohols, 9 the reactions was shown to follow different courses. However, owing to the synthetic and…”

A Facile Linking of the Pyrrole Ring with Functionalized 3(2H)-Furanone Moieties

“…However, as far as we know, just one publication mentioned indoles linked to the 3(2Н)-furanone scaffold. 21 To develop a general approach to the linking of the pyrrole and 3(2Н)-furanone entities, we have tried to apply the 3(2Н)-furanone construction from carboxylic acids and cyanopropargylic alcohols 22 to pyrrole-and indole-2-carboxylic acids thereby additionally aiming to substantially extend the scope of this reaction. We understand that higher reactivity and basic nature of the pyrrole ring could interfere or even preclude this reaction.…”