30923-82-1Relevant academic research and scientific papers
N-alkylation of amines by homogeneous ruthenium complexes in the presence of free diphosphines
Tamaddoni Jahromi, Bahareh,Kharat, Ali Nemati
, p. 3498 - 3508 (2014/01/06)
Chemoselective N-alkylation of amines by ruthenium complexes in the presence of free diphosphine ligands under mild conditions is described. Octyl amine and aniline were chosen as aliphatic and aromatic amines to investigate the effect of different phosphines, reaction times, and temperature on conversion, as well as selectivity towards related secondary and tertiary amines. After optimization of the reaction conditions, this catalytic system was used for N-alkylation of other amines and has shown moderate to very good yields. The reaction products were monitored by GC-MS. The crystal structure of [Ru(NO3)2CO(PPh3)2] with a monodentate and a bidentate nitrate was determined by X-ray crystallographic analysis.
Nonlinear taft polar free energy relationship: Reactions of N-substituted benzyl amines with benzyl bromide in methanol
Ravi,Sanjeev,Jagannadham
, p. 803 - 810 (2013/11/19)
The rates of reactions of N-substituted benzyl amines with benzyl bromide were measured using a conductivity technique in methanol medium. The reaction followed a total second-order path. The end product of the reaction is identified as dibenzyl alkyl amine (C6H5CH 2N(R)CH2C6H5). The rates increased with a decrease in the electron-donating capacity or with an increase in the Taft σ* value of electron-donating alkyl substituents (R) such as t-butyl (σ* = -0.3), i-propyl (σ* = -0.19), n-butyl (σ* = -0.13), and ethyl (σ* = -0.1) on nitrogen of the amine until the Taft σ* value becomes zero for the methyl group (σ CH 3* = 0.00), and then the rates decreased with an increase in the electron-withdrawing capacity or with an increase in the Taft σ* value of electron-withdrawing substituents (R) such H and C6H 5 (σH* = 0.49 and σC6H5= 0.6). The locus of the Taft polar free energy relationship has a maximum near the point for N-methyl benzyl amine, showing that there is a sharp change in the rate-determining step. A mechanism involving formation of an SN2-type transition state between the amine nucleophiles and the benzyl bromide and its subsequent decomposition is proposed. Activation parameters were calculated and are discussed.
Mechanistic studies of the copper-catalyzed electrophilic amination of diorganozinc reagents and development of a zinc-free protocol
Campbell, Matthew J.,Johnson, Jeffrey S.
, p. 1521 - 1524 (2008/02/02)
Equation Presented An SN2 mechanism for the copper-catalyzed amination of diorganozinc reagents by O-benzoyl-N,N-dialkylhydroxyamines is supported by following stereochemically defined organometallics through the reaction and by employing the endocyclic restriction test. A copper-catalyzed electrophilic amination of organomagnesium compounds is also described in which the use of zinc halides has been eliminated.
Copper-catalyzed electrophilic amination of organozinc nucleophiles: Documentation of O-benzoyl hydroxylamines as broadly useful R2N(+) and RHN(+) synthons
Herman, Ashley M.,Johnson, Jeffrey S.
, p. 219 - 224 (2007/10/03)
This paper details new copper-catalyzed electrophilic amination reactions of diorganozinc reagents using O-benzoyl hydroxylamines as electrophilic nitrogen sources that may be accessed in one step. Simple and functionalized aryl, heteroaryl-, benzyl, n-alkyl, sec-alkyl, and tert-alkyl nucleophiles couple with R2NOC(O)Ph and RHNOC(O)Ph reagents in the presence of catalytic quantities of copper salts to provide tertiary and secondary amines, respectively, in generally good yields. In many cases, the product may be isolated analytically pure after a simple extractive workup. The amination process is shown to tolerate a significant degree of steric demand. The amination of nominally unreactive Caryl-H bonds via a sequential directed ortho metalation/transmetalation/catalytic amination reaction sequence is detailed. The direct Cu-catalyzed amination of Grignard reagents using cocatalysis by ZnCl2 is described.
Copper-Catalyzed Electrophilic Amination of Diorganozinc Reagents
Berman, Ashley M.,Johnson, Jeffrey S.
, p. 5680 - 5681 (2007/10/03)
The copper-catalyzed electrophilic amination of diorganozinc reagents employing O-acyl N,N-dialkyl hydroxylamine derivatives as aminating agents is described. This reaction offers a general method for the preparation of tertiary amines in high yields and is noteworthy for its convenience both in terms of reaction conditions employed (room temperature, ≤1 h) and ease of product isolation (acid/base extractive workup). Copyright
Chemoselective debenzylation of N-benzyl tertiary amines with ceric ammonium nitrate
Bull, Steven D.,Davies, Stephen G.,Fenton, Carry,Mulvaney, Andrew W.,Shyam Prasad,Smith, Andrew D.
, p. 3765 - 3774 (2007/10/03)
Treatment of a range of N-benzyl tertiary amines with aqueous eerie ammonium nitrate results in N-debenzylation to afford the corresponding secondary amine. Chemoselective mono-W-debenzylation of N-benzyl tertiary amines is shown to occur in the presence of N-benzyl amides, O-benzyl ethers, O-benzyl esters, O-benzyl phenolates and 5-benzyl ethers. The Royal Society of Chemistry 2000.
Intramolecular motions in a series of crystalline benzylammonium bromides and dibenzylamines studied by CP/MAS NMR
Riddell, Frank G.,Rogerson, Martin
, p. 493 - 504 (2007/10/03)
A series of 15 compounds including ammonium bromides containing one or two benzyl groups with H, methyl, isopropyl, tert-butyl and tert-amyl substituents and dibenzylamihe with N-isopropyl-, N-tert-butyl- and N-tert-amyl substituents have been synthesised and studied by CP/MAS NMR. The results of dynamic NMR studies on the solids suggest that there is a dramatically wide range of molecular motions occurring in this simple series of compounds: A combination of 2D CPEXSY, dynamic line shape analyses and T1ρ measurements reveals the considerable extent of intramolecular group motions including rotations of methyl, tert-butyl, tert-amyl and phenyl groups. Rates of rotation and activation parameters for these molecular motions are derived where appropriate. In the case of benzyl-tert-butylammonium bromide, where two independent molecules of the compound exist in the asymmetric unit it is shown that the independent processes of tert-butyl rotation in the two molecules have vastly different activation energies that differ by ca. 16 kJ mol-1. The extent of the motions observed suggests that commonly held prejudices about the rigidity of molecules in crystalline solids need revising.
WCl6/LiAlH4 PROMOTED TRANSFORMATION OF IMINES INTO SECONDARY AND TERTIARY AMINES
Ikariya, Takao,Ishikawa, Yasutoshi,Hirai, Kiyomiki,Yoshikawa, Sadao
, p. 311 - 316 (2007/10/02)
The reaction of WCl6/LiAlH4 with imines, R'N=CHR, gave tertiary amines, R'N(CH2R)2, and secondary amines, R'NHCHRCH2R.Isotope labeling experiments revealed that the reaction involved two types of azatungstenacyclobutanes, , produced from the reaction of an alkylidene tungsten intermediate with the imine C=N double bond.Formation of these metallacyclobutanes is highly dependent on the solvent used.
