82024-47-3Relevant articles and documents
Lithium Dicyclohexylamide in Transition-Metal-Free Fischer-Tropsch Chemistry
Xu, Maotong,Qu, Zheng-Wang,Grimme, Stefan,Stephan, Douglas W.
supporting information, p. 634 - 638 (2021/01/25)
Lithium dicyclohexylamide (Cy2NLi) reacts with syn-gas or CO to generate transient intermediates with carbene character, which are capable of reacting further with CO or H2, effecting sequential C-C and C-H bond formations from CO or H2, thus providing a transition-metal-free avenue to the fundamental reactions of the Fischer-Tropsch process. Further experimental and computational data indicate that reactions with CO and H2 are thermodynamically accessible, with a kinetic bias toward CO homologation.
Aggregation Studies of Lithium Dialkylamides. The Role of Aggregates in the Carbonylation Reaction
Nudelman, N. S.,Lewkowicz, E.,Furlong, J. J. P.
, p. 1847 - 1852 (2007/10/02)
13C NMR spectroscopy and isotopic exchange in carbonylation intermediates have been successfully employed to characterize aggregation of lithium dialkylamides in THF solution.It is shown that lithium (3-oxapentamethylene)amide forms a 1 : 1 mixed aggregate with morpholine.The aggregate remains even in diluted THF solution.Lithium pentamethyleneamide also forms aggregates with piperidine while the less acidic amines do not form mixed aggregates with the corresponding lithium dialkylamide either in the solid state or in THF solution.The product composition in the carbonylation reaction of lithium dialkylamides is highly dependent on their aggregation states, and this phenomenon can be successfully used for synthetic purposes.
Relative Acidity and Basicity of Amines in Tetrahydrofuran and the Influence of these Factors on the Carbonylation of Lithium Amides
Furlong, Jorge J.,Lewkowicz, Elizabeth S.,Nudelman, Norma S.
, p. 1461 - 1465 (2007/10/02)
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.
Carbon-Carbon Bond Formation through the Carbonylation of Lithium Dialkylamides. One Pot Synthesis of N-Alkyl-Substituted Formamides, Glyoxylamides, and Hydroxymalonamides
Perez, Daniel G.,Nudelman, N. Sbarbati
, p. 408 - 413 (2007/10/02)
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.
Insertion of Carbon Monoxide into Lithium-Nitrogen Bonds. One-Pot Synthesis of Dialkylformamides and Dialkylglyoxylamides
Nudelman, N. Sbarbati,Perez, Daniel
, p. 133 - 134 (2007/10/02)
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.
