A Simple Synthesis of Enaminones from Reaction between Isocyanides and Cyclic 1,3-dicarbonyl Compounds

Abstract

Polarised olfinic systems are synthesised from the reaction between alkyl or aryl isocyanides and cyclic 1, 3-dicarbonyl compounds such as thiobarbituric acid, 5,5-dimethylcyclohexane-1,3-dione and cyclopentane-1,3dione in good yield.

Three-Component Reaction between alkyl(aryl) Isocyanides and Dialkyl Acetylenedicarboxylates in the Presence of Ethyl Trifluoroacetate

“…20,21 There are a number of reports of iminolactones synthesis. [22][23][24] In continuation of our previous works on IMCRs, [25][26][27][28][29][30][31][32][33] we now report the result of our investigation of the reaction between alkyl(aryl) isocyanides 1 and dialkyl acetylenedicarboxylates 2 in the presence of ethyl trifluoroacetate 3 in refluxing CH 2 Cl 2 .…”

N,N-Dimethylformamide-Promoted Reaction of Isocyanides and Barbituric acids: An Easy Synthesis of 5-[(Alkyl or Arylamino)Methylene]Barbituric Acids

“…The products 4c-4e and 4i-4l are known compounds, which were identified by IR and 1 H NMR spectral data and comparing their melting points with literature reports. 11,13 Typical procedure for the preparation of 4a To a solution of 2-thiobarbituric acid (0.144 g, 1.0 mmol) in DMF (0.5 mL) in a screw-capped vial was added tert-octyl isocyanide (0.140 g, 1 mmol) via a syringe and was shaken for 1 min. The reaction mixture was then kept for about 30 min at room temperature (25 °C) and the completion of reaction was confirmed by TLC (EtOAc-hexane 1:1).…”

“…The main advantages of this methodology with respect to the other methods 9,11,12,[19][20][21][22] are: (i) the reaction is simple to perform; (ii) the reaction occurs at room temperature; (iii) the yields are good to high; (iv) there is no need for any other catalyst;…”

One-pot, three component reactions between isocyanides and dialkyl acetylenedicarboxylates in the presence of phenyl isocyanate: synthesis of dialkyl 2-(alkyl/arylimino)-2,5-dihydro-5-oxo-1-phenyl-1H-pyrrole-3,4-dicarboxylate

“…[8][9][10] The reaction of isocyanides with carbon-carbon triple bonds occurs in a stepwise manner through a zwitterionic intermediate, the ultimate fate of which appears to be dictated by the nature of original triple-bonded substrate. [11][12][13][14][15][16][17][18][19] In continuation of our interest in the application of isocyanides in heterocyclic synthesis, [20][21][22][23][24][25][26][27] we now report the reaction between alkyl/aryl isocyanides 1 and dialkyl acetylenedicarboxylate 2 in the presence of phenyl isocyanate. This one-pot, three component synthesis proceeded spontaneously at 38 ºC in CH 2 Cl 2 and leads to dialkyl 2-(alkyl/arylimino)-2,5-dihydro-5-oxo-1-phenyl-1H-pyrrole derivatives 3a-h (Scheme 1).…”