Carbon-Carbon Bond Formation through the Carbonylation of Lithium Dialkylamides. One-Pot Synthesis of N-Alkyl-Substituted Formamides, Glyoxylamides, and Hydroxymalonamides
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 react...
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| Autores principales: | , |
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| Formato: | JOUR |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00223263_v53_n2_p408_Perez |
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| Sumario: | 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 of the reaction mixture with oxygen after the carbon monoxide absorption has ceased and before the regular workup. © 1988, American Chemical Society. All rights reserved. |
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