(3+2) Cycloaddition of N-benzylazomethine methylide with 4-arylidene-1H-imidazol-5(4H)-ones

[3+2] Cycloaddition of N‐benzylazomethine Methylide with Various Arylidene‐Azolones

“…The revealed stereoselectivity correlates well with previously obtained data, when the most thermodynamically stable cis-and trans-isomers, were also obtained for imidazolones and N-substituted hydantoins, respectively. [28,29] Finally, to confirm the proposed greater stability of the obtained isomers and to predict the possible structure of the derivatives 8, we compared the single point energies of two possible diastereomeric forms for compounds 5-8 a obtained from geometric optimization using Density Functional Theory (DFT) (see SI, Part 6). This assessment confirmed the greater stability of the cis-form for rhodanines 5 and the trans-form for thiohydantoins 7.…”

“…In particular, cycloaddition of various azolones with exocyclic double bond is very promising strategy for the creation of spirocyclic core (Scheme 2). [20,22–27] Among others, such a simple and readily available reagent as N‐benzyl‐1‐(trimethylsilyl)‐N‐(methoxymethyl)methanamine (compound I , Scheme 2), which easily generates N ‐benzylazomethine methylide, is of special interest [15,28,29] . It is used for the synthesis of tetrahydropyrroles (pyrrolidines) that are unsubstituted at the second and fifth positions.…”

Synthesis of Spiro[imidazole‐4,3′‐pyrrolo[1,2‐a]quinolin]‐ 5‐ones via 1,3‐Dipolar Cycloaddition of Quinolinium Ylides with Arylydeneimidazol‐4‐ones

“…The choice of thienyl derivative was made due to its moderately donating nature of its substituent. We have previously shown that substrates 1 with electron‐donating groups are less reactive in cycloaddition reactions, and thus require more robust conditions than those with neutral and acceptor groups [36] . In this view, optimization on the derivative 1 a is rational for providing the most general reaction conditions.…”

“…Recently, we have discovered that cycloaddition products A , derived from quinoline ylides and arylidenecyanocinnamic amides, are potent inhibitors of HIV‐1 integrase (Scheme 1, b ) [35] However, derivatives such as A appeared to have limited stability. At the same time we have demonstrated that arylideneimidazolones are able to react with unstabilized azomethine ylides [36] . forming spirocyclic derivatives.…”

“…At the same time we have demonstrated that arylideneimidazolones are able to react with unstabilized azomethine ylides. [36] forming spirocyclic derivatives. Based on this experience, we expect that sprocyclic cycloadducts of arylideneimidazolones with quinoline ylides would be more stable towards oxidation and acid-promoted processes.…”