A Comprehensive Study on the Reductive Amination of 5‐Hydroxymethylfurfural into 2,5‐Bisaminomethylfuran over Raney Ni Through DFT Calculations

ChemCatChem ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2649-2656 ◽  
Author(s):  
Kuo Zhou ◽  
Haiyan Liu ◽  
Huimin Shu ◽  
Shuwen Xiao ◽  
Dechao Guo ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Reductive Amination ◽  
Raney Ni ◽  
Comprehensive Study

scholarly journals Comprehensive study on the degradation of ochratoxin A in water by spectroscopic techniques and DFT calculations

RSC Advances ◽  
2019 ◽  
Vol 9 (34) ◽  
pp. 19844-19854 ◽  
Author(s):  
Iris Cagnasso ◽  
Glauco Tonachini ◽  
Silvia Berto ◽  
Agnese Giacomino ◽  
Luisa Mandrile ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Ochratoxin A ◽  
Lactone Ring ◽  
Degradation Process ◽  
Spectroscopic Techniques ◽  
Comprehensive Study

The OTA degradation process becomes irreversible only if, following hydrolyzation of the lactone ring, the molecule fragments.

One‐step reductive amination of 5‐hydroxymethylfurfural into 2,5‐bis(aminomethyl)furan over Raney Ni

ChemSusChem ◽  
2021 ◽  
Author(s):  
Zuojun Wei ◽  
Yuran Cheng ◽  
Kou Zhou ◽  
Yue Zeng ◽  
En Yao ◽  
...  
Keyword(s):  
Reductive Amination ◽  
Raney Ni ◽  
One Step

A Modular and Diastereoselective 5+1 Cyclization Approach to N-(Hetero)Aryl Piperidines

2019 ◽  
Author(s):  
Matthew Larsen ◽  
Elisabeth Hennessy ◽  
Madeleine Deem ◽  
Yu-hong Lam ◽  
Josep Saurí ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Reductive Amination ◽  
Michael Reaction ◽  
De Novo ◽  
Heterocyclic Amine ◽  
Reaction Sequence ◽  
Ring Systems ◽  
Rapid Construction

A new general <i>de novo</i> synthesis of pharmaceutically important <i>N</i>-(hetero)aryl piperidines is reported. This protocol uses a robustly diastereoselective reductive amination/aza-Michael reaction sequence to achieve rapid construction of complex polysubstituted ring systems starting from widely available heterocyclic amine nucleophiles and carbonyl electrophiles. Notably, the diastereoselectivity of this process is enhanced by the presence of water, and DFT calculations support a stereochemical model involving a facially selective protonation of a water-coordinated enol intermediate.

A Modular and Diastereoselective 5+1 Cyclization Approach to N-(Hetero)Aryl Piperidines

2019 ◽  
Author(s):  
Matthew Larsen ◽  
Elisabeth Hennessy ◽  
Madeleine Deem ◽  
Yu-hong Lam ◽  
Josep Saurí ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Reductive Amination ◽  
Michael Reaction ◽  
De Novo ◽  
Heterocyclic Amine ◽  
Reaction Sequence ◽  
Ring Systems ◽  
Rapid Construction

A new general <i>de novo</i> synthesis of pharmaceutically important <i>N</i>-(hetero)aryl piperidines is reported. This protocol uses a robustly diastereoselective reductive amination/aza-Michael reaction sequence to achieve rapid construction of complex polysubstituted ring systems starting from widely available heterocyclic amine nucleophiles and carbonyl electrophiles. Notably, the diastereoselectivity of this process is enhanced by the presence of water, and DFT calculations support a stereochemical model involving a facially selective protonation of a water-coordinated enol intermediate.

Synthesis of 1,2-propanediamine via reductive amination of isopropanolamine over Raney Ni under the promotion of K2CO3

2019 ◽  
Vol 73 (8) ◽  
pp. 2019-2026
Author(s):  
Qin-Wei Yu ◽  
Ya-Ni Li ◽  
Qian Zhang ◽  
Wei-Qiang Wang ◽  
Su-Ning Mei ◽  
...  
Keyword(s):  
Reductive Amination ◽  
Raney Ni

scholarly journals A comprehensive study of olefin metathesis catalyzed by Ru-based catalysts

2015 ◽  
Vol 11 ◽  
pp. 1767-1780 ◽  
Author(s):  
Albert Poater ◽  
Luigi Cavallo
Keyword(s):  
Dft Calculations ◽  
Olefin Metathesis ◽  
Second Generation ◽  
Phosphine Ligands ◽  
Grubbs Catalyst ◽  
Heterocyclic Ligand ◽  
Grubbs Catalysts ◽  
Wide Range ◽  
First And Second Generation ◽  
Comprehensive Study

During a Ru-catalyzed reaction of an olefin with an alkylidene moiety that leads to a metallacycle intermediate, the cis insertion of the olefin can occur from two different directions, namely side and bottom with respect to the phosphine or N-heterocyclic ligand (NHC), depending on the first or second generation Grubbs catalyst. Here, DFT calculations unravel to which extent the bottom coordination of olefins with respect is favored over the side coordination through screening a wide range of catalysts, including first and second generation Grubbs catalysts as well as the subsequent Hoveyda derivatives. The equilibrium between bottom and side coordination is influenced by sterics, electronics, and polarity of the solvent. The side attack is favored for sterically less demanding NHC and/or alkylidene ligands. Moreover the generation of a 14-electron species is also discussed, with either pyridine or phosphine ligands to dissociate.

Progress In The Practical Application Of Automated Image Analysis To Tem Negatives

1977 ◽  
Vol 35 ◽  
pp. 214-217
Author(s):  
F. A. Heckman ◽  
E. Redman ◽  
J.E. Connolly
Keyword(s):  
Image Analysis ◽  
Image Quality ◽  
Exposure Time ◽  
Image Contrast ◽  
Automated Image Analysis ◽  
Practical Application ◽  
Factors Affecting ◽  
High Image Quality ◽  
Qualitative Evidence ◽  
Comprehensive Study

In our initial publication on this subject1) we reported results demonstrating that contrast is the most important factor in producing the high image quality required for reliable image analysis. We also listed the factors which enhance contrast in order of the experimentally determined magnitude of their effect. The two most powerful factors affecting image contrast attainable with sheet film are beam intensity and KV. At that time we had only qualitative evidence for the ranking of enhancing factors. Later we carried out the densitometric measurements which led to the results outlined below.Meaningful evaluations of the cause-effect relationships among the considerable number of variables in preparing EM negatives depend on doing things in a systematic way, varying only one parameter at a time. Unless otherwise noted, we adhered to the following procedure evolved during our comprehensive study:Philips EM-300; 30μ objective aperature; magnification 7000- 12000X, exposure time 1 second, anti-contamination device operating.

Hexachlorobenzene toxicity in the monkey ovary: III. Ultrastructure induced by high (10 mg/kg) dose exposure

1991 ◽  
Vol 49 ◽  
pp. 130-131
Author(s):  
A. Singh ◽  
A. Dykeman ◽  
J. Jarrelf ◽  
D. C. Villeneuve
Keyword(s):  
Present Report ◽  
Reproductive Toxicity ◽  
Control Group ◽  
Primate Model ◽  
Human Follicular Fluid ◽  
Thin Sections ◽  
Cynomolgus Monkeys ◽  
Cacodylate Buffer ◽  
Induction Cycle ◽  
Comprehensive Study

Hexachlorobenzene (HCB), a persistent and mobile organochlorine pesticide, occurs in environment. HCB has been shown to be present in human follicular fluid. An objective of the present report, which is part of a comprehensive study on reproductive toxicity of HCB, was to determine the cytologic effects of the compound on ovarian follicles in a primate model.Materials and Methods. Eight Cynomolgus monkeys were housed under controlled conditions at Animal facility of Health and Welfare, Ottawa. Animals were orally administered gelatin capsules containing HCB mixed with glucose in daily dosages of 0.0 or 10 mg/kg b.w. for 90 days; the former was the control group. On the menstrual period following completion of dosing, the monkeys underwent an induction cycle of superovulation. At necropsy, one-half of an ovary from each animal was diced into ca. 2- to 3-mm cubed specimens that were fixed by immersion in 2.5% glutaraldehyde in 0.1 M cacodylate buffer (pH 7.3). Subsequent procedures followed to obtain thin sections that were examined in a Hitachi H-7000 electron microscope have been described earlier.

Comparison of Substructures Between Uniaxial and Biaxial Deformation in 1100-0 Aluminum

1981 ◽  
Vol 39 ◽  
pp. 52-53
Author(s):  
D. L. Rohr ◽  
S. S. Hecker
Keyword(s):  
Plastic Strain ◽  
Cell Walls ◽  
Room Temperature ◽  
Mechanical Response ◽  
Biaxial Tension ◽  
Initial Deformation ◽  
Uniaxial Deformation ◽  
Biaxial Deformation ◽  
Stress States ◽  
Comprehensive Study

As part of a comprehensive study of microstructural and mechanical response of metals to uniaxial and biaxial deformations, the development of substructure in 1100 A1 has been studied over a range of plastic strain for two stress states.Specimens of 1100 aluminum annealed at 350 C were tested in uniaxial (UT) and balanced biaxial tension (BBT) at room temperature to different strain levels. The biaxial specimens were produced by the in-plane punch stretching technique. Areas of known strain levels were prepared for TEM by lapping followed by jet electropolishing. All specimens were examined in a JEOL 200B run at 150 and 200 kV within 24 to 36 hours after testing.The development of the substructure with deformation is shown in Fig. 1 for both stress states. Initial deformation produces dislocation tangles, which form cell walls by 10% uniaxial deformation, and start to recover to form subgrains by 25%. The results of several hundred measurements of cell/subgrain sizes by a linear intercept technique are presented in Table I.

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