113515-64-3Relevant academic research and scientific papers
Borrowing Hydrogen-Mediated N-Alkylation Reactions by a Well-Defined Homogeneous Nickel Catalyst
Bains, Amreen K.,Kundu, Abhishek,Yadav, Sudha,Adhikari, Debashis
, p. 9051 - 9059 (2019/10/02)
We report herein a well-defined and bench-stable azo-phenolate ligand-coordinated nickel catalyst which can efficiently execute N-alkylation of a variety of anilines by alcohol. We demonstrate that the redox-active azo ligand can store hydrogen generated during alcohol oxidation and redelivers the same to an in-situ-generated imine bond to result in N-alkylation of amines. The reaction has wide scope, and a large array of alcohols can directly couple to a variety of anilines. Mechanistic studies including deuterium labeling to the substrate establishes the borrowing hydrogen method from alcohols and pinpoints the crucial role of the redox-active azo moiety present on the ligand backbone. Isolation of the ketyl intermediate in its trapped form with a radical quencher and higher kH/kD for the alcohol oxidation step suggest altogether a hydrogen-atom transfer (HAT) to the reduced azo backbone to pave alcohol oxidation as opposed to the conventional metal-ligand bifunctional mechanism. This example clearly demonstrates that an inexpensive base metal catalyst can accomplish an important coupling reaction with the help of a redox-active ligand backbone.
Synthesis, structure, and stereodynamics of an N,N-chiral 'proton sponge'
Charmant, Jonathan P. H.,Lloyd-Jones, Guy C.,Peakman, Torren M.,Woodward, Robert L.
, p. 2501 - 2510 (2007/10/03)
1,8-Bis(N-benzyl-N-methylamino)naphthalene (2) and its hydrogen iodide salt [2H]+[I]- were synthesised from 1,8-diaminonaphthalene. The thermodynamic diastereomer ratios of (2) and [2H]+ in [D7]DMF are 73.4:26.6 and 89.7:10.3 respectively at 293 K. The solid state structures of the major dl-(R(N)R(N)/S(N)S(N)) diastereomers were determined by single crystal X-ray diffraction. The minor diastereomers were shown to be the meso-(R(N)S(N)) forms by performing 1H-NMR NOE studies on isotopically desymmetrized 1-(N- benzyl-N-[13C]-methylamino)-8-(N'-benzyl-N'-methylamino)naphthalene [13C]-2 and the salt [13C]-[2H]+. In [D7]DMF at 298 K, the meso form of the free base 2 is 0.6 (± 0.07) kcal · mol-1 less stable than the d1 form (ΔH°= -0.64 (±0.03) kcal · mol-1; ΔS°= -0.18 (±0.13) cal · K- 1mol-1) and the activation barriers for interconversion are ca. 14,2 (±0.4) and 14,8 (±0.4) kcal · mol-1 respectively. The effect of solvent polarity on the entropy and enthalpy change on approach to the transition state was studied. An approximate correlation with the solvent dielectric constant was found for both ΔH((+)) and ΔS((+)) and this may be ascribed to the development of a net dipole in the transition state due to substantially different hybridisation and geometry at the two nitrogen centres.
Synthesis of a protonated C2-symmetric N,N-chiral 'proton sponge'
Charmant, Jonathan P. H.,Lloyd-Jones, Guy C.,Peakman, Torren M.,Woodward, Robert L.
, p. 4733 - 4736 (2007/10/03)
The hydrogen iodide salt of 1,8-bis-(N-benzyl-N-methylamino)naphthalene was synthesised as an 89 / 11 ratio of diastereomers in good yield. The structure of the major (±)-(R(N)R(N)/S(N)S(N)) diastereomer was determined by single crystal X-ray diffraction. The minor diastereomer is shown to be the meso-(R(N)S(N)) form by performing 1H NMR n.O.e studies on isotopically desymmetrized 1-(N-benzyl-N-[13C]-methylamino)-8-(N'-benzyl-N'- methylamino)naphthalene (HI salt). The half-life of interconversion of meso and dl forms is less than 2 minutes in CD2Cl2 at ambient temperature.
PERI-NAPHTHYLENEDIAMINES XII. ELIMINATION OF THE μ-CARBONYL GROUP IN 1,3-DIALKYLPERIMIDONES AND IMIDAZOLONES. A CONVENIENT METHOD FOR THE SYNTHESIS OF N,N'-DIALKYL DERIVATIVES OF PERI- AND ORTHO-DIAMINES
Konstantinchenko, A. A.,Pozharskii, A. A,,Stepanova, V. N.
, p. 1195 - 1199 (2007/10/02)
N,N'-Dialkyl-substituted 1,8-diamino- and 1,2-diaminonaphthalenes are formed with good yields when the 1,3-dialkyl derivatives of perimidone and naphthoimidazolone are fused with anhydrous powdered alkali at 200-220 deg C.Sodium amide in dimethylaniline can be used instead of the alkali.
