- One-Pot Synthesis of N,N,N',N'-Tetrasubstituted Ureas and Oxomalonamides by Oxidative Carbonylation of Lithium Amides at Atmospheric Pressure
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N,N,N',N'-tetrasubstituted ureas have been obtained in good yields by reaction of lithium aliphatic amides in tetrahydrofuran solution with carbon monoxide under mild conditions (0 deg C, 1013 mbar) followed by treatment with oxygen prior to work up.N,N,N',N'-tetrasubstituted oxomalonamides (oxopropanediamides) can be obtained under similar reaction conditions by carrying out the reaction in the presence of known amounts of the pure amine.Besides being an useful synthetic method, the present studies afford new evidence of the mechanism of the reaction.
- Nudelman, Norma S.,Lewkowicz, Elizabeth S.,Perez, Daniel G.
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p. 917 - 920
(2007/10/02)
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- Relative Acidity and Basicity of Amines in Tetrahydrofuran and the Influence of these Factors on the Carbonylation of Lithium Amides
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The equilibrium constants for the ion-pair formation between 2,4-dinitrophenol and the following amines: pyrrolidine, piperidine, dibutylamine, di-isopropylamine, cyclohexylisopropylamine, dicyclohexylamine, morpholine, and diethylamine, in tetrahydrofuran (THF) have been measured.The relative acidities of the same amines (except diethylamine) have been also determined, as well as the pKa-values for di-isopropylamine, cyclohexylisopropylamine, and dicyclohexylamine in THF.The results show the importance of acid-base equilibria in determining the product distribution in the carbonylation of lithium amides in THF.They also explain the role of the : ratio in determining the reaction products.
- Furlong, Jorge J.,Lewkowicz, Elizabeth S.,Nudelman, Norma S.
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p. 1461 - 1465
(2007/10/02)
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- Carbon-Carbon Bond Formation through the Carbonylation of Lithium Dialkylamides. One Pot Synthesis of N-Alkyl-Substituted Formamides, Glyoxylamides, and Hydroxymalonamides
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The reaction of lithium dialkylamides 1 (dialkyl = dibutyl, dipentyl, dicyclohexyl, 3-oxapentamethylene, and isopropyl cyclohexyl) with carbon monoxide was examined under several reaction conditions.It is shown that the corresponding lithium carbamoyl is the first intermediate and its further reactions can lead to dialkylformamides 2, dialkylglyoxylamides 3, or tetraalkylhydroxymalonamides 4.Dialkylamides were previously assumed to come from hydrolysis of lithium carbamoyls, and these represent an unexplained "island of stability" among the area of acyl anions.Evidence is given that casts doubts on this assumption and suggests that 2 comes from the cleavage of lithium tetraalkylurea dianion.The yields of 2, 3, or 4 obtained by this one-step, rapid procedure are much higher than those afforded by the usual several steps methods of preparation, especially for compounds 3 and 4.Tetraalkylureas, tetraalkyloxalamines, or tetraalkylketomalonamides can be obtained in good yield by the same general procedure, followed by treatment ot the reaction mixture with oxygen after the carbon monoxide absorption has ceased and before the regular workup.
- Perez, Daniel G.,Nudelman, N. Sbarbati
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p. 408 - 413
(2007/10/02)
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- Insertion of Carbon Monoxide into Lithium-Nitrogen Bonds. One-Pot Synthesis of Dialkylformamides and Dialkylglyoxylamides
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Lithium dialkylamides react with CO to afford dialkylformamides 2, tetraalkylhydroxymalonamides 3, and dialkylglyoxylamides 4.Reaction conditions are described to produce 2 or 4 in good yields.
- Nudelman, N. Sbarbati,Perez, Daniel
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p. 133 - 134
(2007/10/02)
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