59540-56-6Relevant academic research and scientific papers
α-Diamine Nickel Catalysts with Nonplanar Chelate Rings for Ethylene Polymerization
Liao, Heng,Zhong, Liu,Xiao, Zefan,Zheng, Ting,Gao, Haiyang,Wu, Qing
, p. 14048 - 14055 (2016/09/21)
A series of novel α-diamine nickel complexes, (ArNH-C(Me)-(Me)C-NHAr)NiBr2, 1: Ar=2,6-diisopropylphenyl, 2: Ar=2,6-dimethylphenyl, 3: Ar=phenyl), have been synthesized and characterized. X-ray crystallographic analysis showed that the coordination geometry of the α-diamine nickel complexes is markedly different from conventional α-diimine nickel complexes, and that the chelate ring (N-C-C-N-Ni) of the α-diamine nickel complex is significantly distorted. The α-diamine nickel catalysts also display different steric effects on ethylene polymerization in comparison to the α-diimine nickel catalyst. Increasing the steric hindrance of the α-diamine ligand by substitution of the o-methyl groups with o-isopropyl groups leads to decreased polymerization activity and molecular weight; however, catalyst thermal stability is significantly enhanced. Living polymerizations of ethylene can be successfully achieved using 1/Et2AlCl at 35 °C or 2/Et2AlCl at 0 °C. The bulky α-diamine nickel catalyst 1 with isopropyl substituents can additionally be used to control the branching topology of the obtained polyethylene at the same level of branching density by tuning the reaction temperature and ethylene pressure.
The Ti-BINOLate-catalyzed, enantioselective ring-opening of meso-aziridines with amines
Peruncheralathan, Saravanan,Aurich, Sandra,Teller, Henrik,Schneider, Christoph
, p. 2787 - 2803 (2013/05/08)
The titanium-BINOLate-catalyzed, highly enantioselective ring-opening reaction of meso-aziridines has been developed which furnishes trans-1,2-diamines in typically good yields and excellent enantioselectivities. N-Aryl aziridines attached to a 5- or 6-me
Iron-catalyzed ring-opening of meso-aziridines with amines
Marti, Alex,Richter, Luise,Schneider, Christoph
experimental part, p. 2513 - 2516 (2011/11/13)
A cationic iron complex has been found to catalyze the aminolysis of meso-N-aryl aziridines very efficiently furnishing valuable 1,2-diamines in typically excellent yields. This protocol is compatible with a range of functional groups both in the aziridine and amine components. Georg Thieme Verlag Stuttgart · New York.
A Novel Method for the Synthesis of Symmetrical Vicinal Tertiary and Secondary Diamines
Katritzky, Alan R.,Fan, Wei-Qiang,Fu, Cong
, p. 3209 - 3213 (2007/10/02)
A variety of symmetrical vicinal tertiary and secondary diamines are readily prepared in good to excellent yields by either Grignard reaction or reduction of the glyoxal bisproducts with benzotriazole and secondary or primary amines.
β-Substituted Organoalkaline Tri- and Tetra-anions; Preparation, Stability, and Reactivity
Barluenga, Jose,Fananas, Francisco J.,Villamana, Jorge,Yus, Miguel
, p. 2685 - 2692 (2007/10/02)
New β,γ-, β,β'-disubstituted organometallic trianions of the type C(Y)C(Y')C(8) and C(Y)CC(Y') (18) (Y = or (*) Y' = O, PhN), β-substituted organodimetallic trianions of the type CC(PhN)C (25) with alkali-metal cations (Li, Na, and K), and a lithiated tetra-anion of the type CC(PhN)C(PhN)C (32) are obtained from the corresponding substituted organomercury(II) compounds via low-temperature mercury-alkali metal transmetallation.The starting organomercurials can be obtained by solvomercuriation from suitable unsaturated systems.These polyanion derivatives are stable species only at temperatures in the range -78 to -100 deg C; at higher temperatures rapid decomposition takes place via either a β-elimination process or proton abstraction from the reaction media.The new polyanionic compounds are characterized by transformation into their deuterio derivatives with deuterium oxide at low temperature.The thermal decomposition of these organometallic intermediates is also reported.The reactivity of the lithiated trianion derived from isopropylaniline (25a) with different agents (ethyl bromide, dimethyl disulphide, and trimethylchlorosilane) in a successive or simultaneous way is studied; this process occurs in a regioselective manner.
Reduction of Schiff's Bases and Phenylhydrazones by Zinc Dust
Khan, Naseem H.,Zuberi, Rashid H.,Siddiqui, Amin A.
, p. 363 - 372 (2007/10/02)
Schiff's bases when subjected to the chemical action of zinc dust and chloroform in ethyl alcohol at steam bath temperature for varying times yield 1,2-diaminophenylethanes in crystalline form and in good yield (Table 1).
