Synthesen mit Nitrilen, LXXXII:Über Spiro[indan‐pyrane] und Inden‐propellane — Addukte von 1,3‐Dicarbonylverbindungen an 2‐(Dicyanmethylen)‐1,3‐indandion

Reaction of N1, N2-diarylamidines with 2-(1,5-dihydro-3-methyl-5-oxo-1-phenyl-4H-pyrazol-4-ylidene) propanedinitrile

“…The upfield shift in the range 52-57 ppm for the sp 2 carbon attached to the nitrile group has been previously reported. 13,14 The most plausible origin of the methylene group is the acetyl methyl group in the acetamidines 8b-d…”

Facile One Pot Microwave Assisted Solvent-Free Synthesis of Novel Spiro-Fused Pyran Derivatives via the Three-Component Condensation of Ninhydrin with Malononitrile and Active Methylene Compounds

“…Structural proof was obtained through a two-component condensation of 4 with 3 under the previous conditions. Further confirmation of structure 7 was made by comparison with an authentic sample, prepared from the reaction of 1 with 2 and 3 using the conventional thermal 28,29 method in refluxing ethanol containing a catalytic amount of piperidine for 4 hours, which showed agreement by MP, IR, and 1 H NMR data. Similarly, 3-methyl-3-pyrazolin-5-one 8 was reacted with 1 and 2 under the previous conditions to give the corresponding spiropyrano [2,3-c]pyrazole 9A, which can exist in the tautomeric form 9B, and its structure was deduced on the basis of analytical and spectral data (Scheme II and Table 1).…”

Cu(ii)-thiophene-2,5-bis(amino-alcohol) mediated asymmetric Aldol reaction and Domino Knoevenagel Michael cyclization: a new highly efficient Lewis acid catalyst

“…82,83 Over the couple years, sizable number of investigation have been carried out successfully for the construction of spiro[4H-pyran-3,3 0 -oxindole] framework as a core skeleton of spirooxindole structures. [90][91][92] Domino Knoevenagel Michael cyclization is one of the highly successful procedures for the stereoselective synthesis of spirooxindole derivatives derived spiro[4H-pyran-3,3 0 -oxindole] moiety. 93,94 To construct this interesting scaffold, Yuan and coworkers in 2010 for the rst time, utilized cupreine-(60hydroxycinchonidine) as organocatalyst for accessing chiral spiro[4H-pyran-3,3 0 -oxindole] derivatives from multi component reactions of N-alkylated isatins.…”