110-95-2Relevant academic research and scientific papers
69. Roentgenstrukturanalyse von 2,4,6-Tri(tert-butyl)phenyllithium*N,N,N',N'-Tetramethylpropan-1,2-diamin: eine monomere Organolithium-Verbindung
Maetzke, Thomas,Seebach, Dieter
, p. 624 - 630 (1989)
Tri(tert-buty)phenyllithium is an important reagent for the preparation of derivatives of main-group elements with low coordination state as well as a highly hindered base for the generation of amine-free Li-enolates.Its monomeric nature in solution was previously deduced from NMR measurements.While Et2O, THF, and N,N,N',N'-tetramethylethylene-1,2-diamine (tmen) led to crystalline samples which were not suitable for structure analysis, the N,N,N',N'-tetramethylpropane-1,2-diamine (tmpn) gave good single crystals of the title compound from Et2O/hexane (disorder along the two-fold crystallographic axis running through Li-C(2) and C(4) of the Ph ring).The structure (Fig. 1, Table 1) has some remarkable features: i) it is one of the very few monomeric organolithium compounds so far, (ν1-Li on aromatic ring): ii) it has the rare trigonal-planar coordiantion of the Li-atom; iii) there are close contacts between the Li-atom and one of the Me groups in each ortho-position (Fig. 3).The internal angle on the Ph-ring ipso-C-atom is 114.This angle as well as those of the other known phenyllithium (Table 2), -magnesium, and -aluminum structures are included in a plot of ipso-angles against Pauling electronegativities.
Fragmentation During the Formic Acid/Formaldehyde (Eschweiler-Clarke) Methylation of Polyamines
Alder, Roger W.,Colclough, David,Mowlam, Rodney W.
, p. 7755 - 7758 (1991)
Eschweiler-Clarke methylations of both acyclic and cyclic polyamines can lead to methylation products of fragments of the original polyamine; thus 1,5,9,13-tetra-azatridecane yields 1,1,3,3-tetramethylpropanediamine exclusively and 1,5,9-triazacyclododecane gives 45 percent 1,5,9-trimethyl-1,5,9-triazacyclododecane and 45 percent 2,6,10-trimethyl-2,6,10-triazaundecane.
Selective oxidation of exogenous substrates by a bis-Cu(III) bis-oxide complex: Mechanism and scope
Large, Tao A.G.,Mahadevan, Viswanath,Keown, William,Stack, T. Daniel P.
, p. 782 - 792 (2019/01/03)
Cu(III)2(μ-O)2 bis-oxides (O) form spontaneously by direct oxygenation of nitrogen-chelated Cu(I) species and constitute a diverse class of versatile 2e?/2H+ oxidants, but while these species have attracted attention as biomimetic models for dinuclear Cu enzymes, reactivity is typically limited to intramolecular ligand oxidation, and systems exhibiting synthetically useful reactivity with exogenous substrates are limited. OTMPD (TMPD = N1, N1, N3, N3-tetramethylpropane-1,3-diamine) presents an exception, readily oxidizing a diverse array of exogenous substrates, including primary alcohols and amines selectively over their secondary counterparts in good yields. Mechanistic and DFT analyses suggest substrate oxidation proceeds through initial axial coordination, followed by rate-limiting rotation to position the substrate in the Cu(III) equatorial plane, whereupon rapid deprotonation and oxidation by net hydride transfer occurs. Together, the results suggest the selectivity and broad substrate scope unique to OTMPD are best attributed to the combination of ligand flexibility, limited steric demands, and ligand oxidative stability. In keeping with the absence of rate-limiting C–H scission, OTMPD exhibits a marked insensitivity to the strength of the substrate Cα–H bond, readily oxidizing benzyl alcohol and 1-octanol at near identical rates.
REDUCTIVE PREPARATION OF TERTIARY DIMETHYLAMINES FROM NITRILES
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Paragraph 0058; 0059, (2017/04/04)
This disclosure describes a low temperature process for the preparation of dimethyl amines from nitriles via reductive amination. In some embodiments, the process proceeds under mild conditions with aqeuous dimethylamine and show an unexpected rate acceleration by the inclusion of an acid addition salt of the dimethylamine.
RANEY nickel-catalyzed reductive N-methylation of amines with paraformaldehyde: Theoretical and experimental study
Ge, Xin,Luo, Chenxi,Qian, Chao,Yu, Zhiping,Chen, Xinzhi
, p. 43195 - 43203 (2015/02/19)
RANEY Ni-catalyzed reductive N-methylation of amines with paraformaldehyde has been investigated. This reaction proceeds in high yield with water as a byproduct. RANEY Ni can be easily recovered and reused with a slight decrease of the yield. Using density functional theory (DFT), the mechanism of RANEY Ni-catalyzed reductive N-methylation is discussed in detail. The reaction pathway involves the addition of amine with formaldehyde, dehydration to form the imine and hydrogenation. In the transition state of hemiaminal dehydration, the C-O bond cleavage of the aromatic amine is more difficult than that of the aliphatic amine. For the aromatic amine, a higher energy barrier must be overcome, which results in a relatively low yield. After addition of amine with formaldehyde and dehydration, imine is obtained and preferred to adsorb on the bridge site of the Ni(111) surface. The preferential pathways of imine hydrogenation involve the pre-adsorbed hydrogen atom attacking the nitrogen atom of the imine. The energy barrier of hydrogenation is much lower than that of addition and dehydration. Thus, the hydrogenation of imine is a relatively rapid reaction step. In the reductive N-methylation of secondary amine, the possible dehydration pathway is different from the one of the primary amine. In the dehydration of the secondary amine, the intermediate hemiaminal is initially adsorbed on the bridge site of the Ni(111) surface, then undergoes C-O bond cleavage, and eventually the hydroxyl is located in the bridge site. With the final hydrogenation, the product is obtained by adsorption on the top site of the Ni(111) surface.
Low pressure process for manufacture of 3-dimethylaminopropylamine (DMAPA)
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Page 4-5, (2008/06/13)
An improved process for the production of 3-dimethylaminopropylamine in high purity from N,N-dimethylaminopropionitrile utilizing a low pressure hydrogenation process is described. The basic process comprises contacting the nitrile with hydrogen at low pressure in the presence of a catalyst under conditions sufficient to effect the conversion of the nitrile to the primary amine product.
Nucleophilicity towards a Vinylic Carbon Atom: Rate Constants for the Addition of Amines to the 1-Methyl-4-vinylpyridinium Cation in Aqueous Solution
Heo, Christina K. M.,Bunting, John W.
, p. 2279 - 2290 (2007/10/02)
Second-order rate constants (kNu) have been measured for the addition of 44 primary amines (including five α-effect amines), 28 secondary amines, 19 tertiary amines, ammonia and hydroxide ion to the vinyl group of the 1-methyl-4-vinylpyridinium cation (1) in aqueous solution at 25 deg C (ionic strength 0.1 mol dm-3).Nucleophilic attack is shown to be rate-determining for primary and secondary amines being generally more reactive than primary amines, with secondary amines of the same basicity.After classification of these species in terms of structure, they describe a number of Broensted-type correlations having βnuc in the range 0.35-0.54 for six structural classes of primary amine, βnuc = 0.48 for α-effect amines, and βnuc in the range 0.23-0.34 for four structural classes of secondary amine.Substitution upon the α-carbon atom reduces amine nucleophilicity of both primary and secondary amines.The presence of an unsaturated carbon atom (either sp2- or sp-hybridized) as the β-carbon atom leads to an enhanced reactivity relative to the corresponding β-sp3 species in all cases.Tertiary amines are in general less reactive than other amines of the same basicity.Broensted-type plots for tertiary amines present the appearance of random scatter which is not readily decipherable in terms of structure. β-Hydroxy and β-amino tertiary amines are unusually reactive relative to their basicity.All of these phenomena suggest that protonation of the carbanionic intermediate by a molecule of water is the rate-determining step for the addition of tertiary amines to 1.Rate constants for the attack of primary and secondary amines on 1 are shown to correlate with literature data for a variety of other reactions involving rate-determining nucleophilic attack of amines upon electrophilic carbon.These kNu for primary and secondary amines reacting with 1 are also shown to correlate with Ritchie's N+ parameters for nucleophilic attack at electrophilic sp2-carbon.N+ parameters for amine nucleophiles have not been widely available previously; the parameters that have been available for selected amines are known to be sensitive to the nature of the defining electrophile.The minimal steric hindrance at the electrophilic centre in nucleophilic attack upon 1 suggests that this species is an appropriate electrophile for the definition of N+ parameters for amine nucleophiles; these parameters are evaluated for 70 primary and secondary amines and ammonia and are suggested to provide an appropriate data base for future investigations of the reactivity and selectivity of amine attack upon sp2-carbon electrophiles in aqueous solution.
Dimethyl(N,N,N′,N′-tetramethylethanediamine)palladium(II) and dimethyl[1,2-bis(dimethylphosphino)ethane]palladium(II): Syntheses, X-ray crystal structures, and thermolysis, oxidative-addition, and ligand-exchange reactions
De Graaf, Wim,Boersma, Jaap,Smeets, Wilberth J. J.,Spek, Anthony L.,Van Koten, Gerard
, p. 2907 - 2917 (2008/10/08)
PdMe2(tmeda) (2a) (tmeda = N,N,N′,N′-tetramethylethanediamine) has been prepared and characterized by means of NMR spectroscopy and X-ray crystallography. Crystals of PdMe2(tmeda) are monoclinic, space group P21/n, with un
