Synthesis of benzopyranopyrrolidines via 1,3-dipolar cycloaddition of nonstabilized azomethine ylides with 3-substituted coumarins

Abstract

a b s t r a c tA three-component reaction of 3-substituted coumarins with N-alkyl-a-amino acids and aldehydes gave 1-benzopyrano[3,4-c]pyrrolidines as a result of a 1,3-dipolar cycloaddition of an intermediate nonstabilized azomethine ylide at the double bond of the coumarin system in moderate to good yields. In most cases, high regio-and stereo-selectivity of the [3þ2] cycloaddition was observed.

Selective Synthesis Dispiro[indoline‐3,2′‐pyrrolidine‐3′,3″‐quinoline] Derivatives and Spiro[imidazole‐4,3′‐quinoline] Derivatives via 1,3‐Dipolar Cycloaddition Reaction

“…After cooling, the precipitate was filtered off, washed with ethanol, and finally dried. peak), 363 (M + À 1, 73), 241 (12), 108 (19), 107 (14).…”

“…The 1,3‐dipolar cycloaddition of azomethine ylide with dipolarophile is the key of many research groups. 1,3‐Dipolar cycloaddition is potential synthetic applications of many compounds such as incorporation of pentafluorosulfanyl group into isoxazoles and isoazolines , lactams, indolizidines, alkaloids , dispirooxindolopyrrolidines , pyrrolines, pyrrolidines , benzopyranopyrrolidines , pyrrolidinyl oxindoles , and dispirooxindolecyclo[pyrrole(1,2‐c)thiazole‐6,5̍‐thiazolidine] derivatives . In the present research, we have examined a new example of a 1,3‐dipolar cycloaddition between azomethine ylide with dipolarophile with a highly electron rich alkene.…”

Synthesis and Chemical Properties of 3-Phosphono-coumarins and 1,2-Benzoxaphosphorins as Precursors for Bioactive Compounds

“…Conjugate addition reactions to 3-diethylphosphonocoumarin 1a using asymmetric nonstabilized azomethine ylides were investigated by Moshkin et al [55,56]. The developed approach for the synthesis of products 28 and 29 utilized as starting material the in situ formed ylide derived from cyclohexanone and N-methylglycine (Scheme 29).…”

Nonstabilized azomethine ylides as reagents for alkylaminomethylation of aromatic ketones via 5-aryloxazolidines

“…In previous publications using coumarins and chromones we observed that nonstabilized azomethine ylides reacted poorly with weak electronwithdrawing or sterically hindered dipolarophiles. 16e, 23 We envisaged that the reactions with more active fluorenone and (trifluoromethyl)phenylketone may produce the corresponding oxazolidines in good yield.…”