20002-22-6Relevant academic research and scientific papers
Switching Selectivity in Copper-Catalyzed Transfer Hydrogenation of Nitriles to Primary Amine-Boranes and Secondary Amines under Mild Conditions
Song, Hao,Xiao, Yao,Zhang, Zhuohua,Xiong, Wanjin,Wang, Ren,Guo, Liangcheng,Zhou, Taigang
, p. 790 - 800 (2022/01/11)
A simple and efficient copper-catalyzed selective transfer hydrogenation of nitriles to primary amine-boranes and secondary amines with an oxazaborolidine-BH3 complex is reported. The selectivity control was achieved under mild conditions by switching the solvent and the copper catalysts. More than 30 primary amine-boranes and 40 secondary amines were synthesized via this strategy in high selectivity and yields of up to 95%. The strategy was applied to the synthesis of 15N labeled in 89% yield.
Mechanistic study on aerobic oxidation of amine over intermetallic Pd3Pb: Concerted promotion effects by Pb and support basicity
Furukawa, Shinya,Suga, Akifusa,Komatsu, Takayuki
, p. 1214 - 1222 (2015/03/04)
A mechanistic study on aerobic oxidation of amine to imine over Pd3Pb/MOx (MOx = SiO2, TiO2, Al2O3, and MgO) intermetallic catalysts was performed to clarify the role of Pb and the support in enhancing catalytic activity. Results from X-ray absorption and photoelectron spectroscopies revealed that formation of the Pd3Pb phase made Pd electron-rich compared to pure Pd, whereas the electronic states of Pd in Pd3Pb/MOx were identical and independent of the nature of the support. Kinetic studies indicated that desorption of imine was promoted by Pb and that adsorption of amine was accelerated by basic sites on the support. Infrared temperature programmed desorption (IR-TPD) experiments demonstrated that desorption of imine was indeed promoted on Pd3Pb compared to Pd. The support effect only appears on Pd3Pb catalysts and not on pure Pd due to change in the rate-determining step from imine desorption to amine adsorption. The combination of Pb and the support basicity provides a unique and highly efficient bifunctional catalysis. (Chemical Equation Presented).
Amine oxidative N-dealkylation via cupric hydroperoxide Cu-OOH homolytic cleavage followed by site-specific fenton chemistry
Kim, Sunghee,Ginsbach, Jake W.,Lee, Jung Yoon,Peterson, Ryan L.,Liu, Jeffrey J.,Siegler, Maxime A.,Sarjeant, Amy A.,Solomon, Edward I.,Karlin, Kenneth D.
, p. 2867 - 2874 (2015/03/14)
Copper(II) hydroperoxide species are significant intermediates in processes such as fuel cells and (bio)chemical oxidations, all involving stepwise reduction of molecular oxygen. We previously reported a CuII-OOH species that performs oxidative N-dealkylation on a dibenzylamino group that is appended to the 6-position of a pyridyl donor of a tripodal tetradentate ligand. To obtain insights into the mechanism of this process, reaction kinetics and products were determined employing ligand substrates with various para-substituent dibenzyl pairs (-H,-H; -H,-Cl; -H,-OMe, and -Cl,-OMe), or with partially or fully deuterated dibenzyl N-(CH2Ph)2 moieties. A series of ligand-copper(II) bis-perchlorate complexes were synthesized, characterized, and the X-ray structures of the -H,-OMe analogue were determined. The corresponding metastable CuII-OOH species were generated by addition of H2O2/base in acetone at -90 °C. These convert (t1/2 ≈ 53 s) to oxidatively N-dealkylated products, producing para-substituted benzaldehydes. Based on the experimental observations and supporting DFT calculations, a reaction mechanism involving dibenzylamine H-atom abstraction or electron-transfer oxidation by the CuII-OOH entity could be ruled out. It is concluded that the chemistry proceeds by rate limiting Cu-O homolytic cleavage of the CuII-(OOH) species, followed by site-specific copper Fenton chemistry. As a process of broad interest in copper as well as iron oxidative (bio)chemistries, a detailed computational analysis was performed, indicating that a CuIOOH species undergoes O-O homolytic cleavage to yield a hydroxyl radical and CuIIOH rather than heterolytic cleavage to yield water and a CuII-O?- species.
Highly efficient aerobic oxidation of various amines using Pd3Pb intermetallic compounds as catalysts
Furukawa, Shinya,Suga, Akifusa,Komatsu, Takayuki
supporting information, p. 3277 - 3280 (2014/03/21)
Intermetallic Pd3Pb supported on Al2O3 can act as a highly efficient heterogeneous catalyst for the oxidation of various amines including primary, secondary, aromatic, aliphatic, and cyclic amines. The Royal Society of Chemistry 2014.
An unprecedented rearrangement in collision-induced mass spectrometric fragmentation of protonated benzylamines
Bialecki, Jason,Ruzicka, Josef,Attygalle, Athula B.
, p. 1195 - 1204 (2007/10/03)
The collision-induced dissociation (CID) mass spectra of several protonated benzylamines are described and mechanistically rationalized. Under collision-induced decomposition conditions, protonated dibenzylamine, for example, loses ammonia, thereby forming an ion of m/z 181. Deuterium labeling experiments confirmed that the additional proton transferred to the nitrogen atom during this loss of ammonia comes from the ortho positions of the phenyl rings and not from the benzylic methylene groups. A mechanism based on an initial elongation of a C-N bond at the charge center that eventually cleaves the C-N bond to form an ion/neutral complex of benzyl cation and benzylamine is proposed to rationalize the results. The complex then proceeds to dissociate in several different ways: (1) a direct dissociation to yield a benzyl cation observed at m/z 91; (2) an electrophilic attack by the benzyl cation within the complex on the phenyl ring of the benzylamine to remove a pair of electrons from the aromatic sextet to form an arenium ion, which either donates a ring proton (or deuteron when present) to the amino group forming a protonated amine, which undergoes a charge-driven heterolytic cleavage to eliminate ammonia (or benzylamine) forming a benzylbenzyl cation observed at m/z 181, or undergoes a charge-driven heterolytic cleavage to eliminate diphenylmethane and an immonium ion; and (3) a hydride abstraction from a methylene group of the neutral benzylamine to the benzylic cation to eliminate toluene and form a substituted immonium ion. Corresponding benzylamine and dibenzylamine losses observed in the spectra of protonated tribenzylamine and tetrabenzyl ammonium ion, respectively, indicate that the postulated mechanism can be widely applied. The postulated mechanisms enabled proper prediction of mass spectral fragments expected from protonated butenafine, an antifungal drug. Copyright
Investigations on the Aprotic Deamination of Benzylamine and (α,α-2H2)Benzylamine
Bakke, Ian M.,Svendsen, K.
, p. 179 - 184 (2007/10/02)
The reaction of benzylamine with nitrosyl chloride in diethyl ether at -50 deg C gave diazotoluene (16percent), benzyl alcohol (15percent), benzyl chloride (31percent) and α,α-azoxytoluene (12percent) together with several other products.The same reaction
