Katalytische reaktionen von aminen mit olefinen

Base-Catalyzed Hydroamination of Olefins: An Environmentally Friendly Route to Amines

“…Thus, the most favorable conditions for the hydroamination are high concentrations of catalyst and olefin, low acidity or high pK a of the amine and high nucleophilicity of the metal amide complex which can be achieved by choosing suitable metal precursors, [15] solvents, [15] and certain additives. [17] Apart from the ionic mechanism described above, an alternative radical mechanism was proposed for certain hydroamination reactions (Scheme 12). It has been argued that if the addition proceeds by an ionic mechanism, the reaction between p-methoxystyrene with aziridine should give the Markovnikov product predominantly; instead, the reaction yielded the anti- …”

“…This reaction was initially described during late 1940×s when a number of patents LiNEt 2 /TMEDA 150 À À À 18 [b] 3 0.23 [17] n-BuLi/KO-t-Bu 120 À À À 45 [b] 4.5 0.23 [27] [a] Conversion. [b] Monohydroamination product.…”

“…[25] It has been shown that additives such as N,N,N',N'-tetramethylethylenediamine (TMEDA) increase the rate of addition of primary and secondary amines to olefins using catalytic amounts of alkyllithium under much lower reaction pressure and temperature than that needed for the metallic sodium catalysts. [17] For example, ethylene reacts with diethylamine in the presence of the LiNEt 2 /TMEDA catalyst system at 70 bar and 140 8C forming triethylamine in 83% yield. However the same reaction in the presence of Na or NaH as catalyst requires 1000 bar pressure and 225 8C to achieve 28% yield.…”

Catalytic Hydroamination of Unsaturated Carbon‐Carbon Bonds

“…Lehmkuhl et al demonstrated the beneficial effect of TMEDA (N,N,N′,N′-tetramethylethylenediamine) on the addition of n-BuNH 2 to ethylene catalyzed by n-BuNHLi (from n-BuNH 2 and EtLi) [121]. This is also true for secondary amines.…”

BiCl3‐Catalyzed Hydroamination of Norbornene with Aromatic Amines

“…As an ongoing project with an aim to discover novel catalysts for olefin hydroamination, we found that only limited attention has been paid to main-group metals in hydroamination reactions. [11] Among the few publications in this field, the recent work of Shibasaki and co-workers has achieved remarkable progress, [12] in which Bi(OTf) 3 was found to be an efficient catalyst for diene and vinylarene hydroaminations. We wondered whether commonly used main-group Lewis acids could also serve as competent catalysts; therefore, we studied the intermolecular hydroamination of norbornene with aromatic amines by using several main-group metal salts.…”