Amines, cyclic diethylamine

Experiments designed to clarify the situation were carried out by Wittig and Mayer (40). It was shown that changing the molar ratio of amine (diethylamine, di- -butylamine, or diisobutylamine) to -butyraldehyde from 1 1 to 2 1 did not affect the yield of enamine (53- 64%, based on the aldehyde). Contrariwise, changing the ratio of amine (morpholine, piperidine, or pyrrolidine) to n-butyraldehyde from 1 1 to 2 1 boosted the yields from 52-57 % to 80-85 %. The authors interpret these data as indicating that the cyclic amines form aminals with n-butyraldehyde, while the open-chain do not. Infrared evidence is stated as having shown that the aminal originates not from attack of excess amine on the enamine, which is stable under the conditions of the reaction, but from the N-hemiacetal (17). 

Amines aniline, cyclic amines, diethylamine, dimethylforamine, EDTA, propanediamine, -propylamine... 

Quinuclidine and DABCO are 40-60 times more reactive than triethylamine. This is again due to the way the ring structures keep the nitrogen s substituents away from interfering with the lone pair as it attacks the electrophile. You should contrast the effect that the cyclic structure has on the pJCaH of the amines none Triethylamine and quinuclidine are equally basic and, as you can see in the margin, so (more or less) are diethylamine, dibutylamine, and piperidine. A proton is so small that it cares very little whether the alkyl groups are tied back or not. 

The use of cyclic enamines" > " " b.436,441,443,446.447, 456.457,470-480 (-g g UQ o ) or dieneamines (e.g., 141 ) yields fused bicyclic systems, although the latter may also yield bis-thietane sulfones. Enamines derived from morpholine, piperidine, pyrrolidine, and dimethylamine are most commonly used, but derivatives of diethylamine, di- -propyl-amine, piperazine, 4-benzylpiperidine, methylpyrrolidines, hexahydroazepin, N-methylaniline, and indoline have also been treated with sulfenes to give thietane sulfones. Asymmetric induction has been observed with the optically active enamine, 142. ... 

Dicyclohexyl tellurium dibromide formed complexes with pyridine, piperidine, mor-phohne, diethylamine, 4-bromoaniline, dimethylformamide, and dimethyl sulfoxide. The complexes have two molecules of ligand per molecule of tellurium compound . Bis[benzoylmethyl] tellurium dibromide formed 1 2 complexes with cyclic amines. ... 

In ahphatic secondary amines this band is too weak to be detected readily. In cyclic bases, for example, only the normal aromatic absorptions are found in this region unless salt formation occurs [58]. Similarly, Barr and Haszeldine [74] could not identify this band in dimethyl or diethylamine, although a band near 1500 cm" was traced in some fluorinated derivatives. Imines with the structure —C=NH are similar to other secondary amides in that any NH deformation absorption shown is extremely weak, but of course they also show an absorption in the same region corresponding to the terminal C=N linkage. 

The preparation of tertiary amines from alkyl halides and a secondary amine, or a primary amine in which both TV-hydre en atoms are to be replaced by identical alkyl groups, can be carried out with favourable yields in many cases, as evidenced by preparations of diethyl-n-hexadecylamine (from diethylamine) and of dimethyl-n-docosylamine (from dimethylamine) . Alkyl sulphonates have similarly been used, and the reaction extended to the preparation of cyclic tertiary amines from primary amines and appropriate terminal di-sulphonates (reaction 38) . Satisfactory conditions have been reported... 

Full details of the Ni - and Pd -catalysed telomerization reactions of butadiene with phenylhydrazones (see Volume 6, p. 388) have now been published. Reaction of butadiene with diethylamine gives (49 Z = NEta) in the presence of allyl M halides. The catalytic activity increases in the series M = Ni < M = Ptsimilar reactions of butadiene, especially virith cyclic secondary amines (e.g. morpholine). For M = Pd addition of AcOH improves the yield of (49 Z = NEta) whilst for M = Pt no telomers are formed in the absence of Al(OR)3 (R = Pr or Bu ) co-catalysts. The reaction of butadiene with acetic acid to give (49 Z = OAc) is also catalysed by [M(cod)2] although with the catalyst M = Pd l-vinylhex-5-enyl acetate is a by-product (20%). Reactions of butadiene with acetaldehyde and phenyl isocyanate in the presence of [Pd(cod)t]-2PPh3 give (50 and (51), respectively, ... 

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