Experimental Study of the Stereomutation of 1,1-Difluoro-2-ethyl-3-methylcyclopropane Confirms the Predicted Preference for Disrotatory Ring Opening and Closure

1998 ◽  
Vol 120 (24) ◽  
pp. 6187-6188 ◽  
Author(s):  
Feng Tian ◽  
Scott B. Lewis ◽  
Michael D. Bartberger ◽  
William R. Dolbier ◽  
Weston Thatcher Borden
Keyword(s):  
Experimental Study ◽  
Ring Opening

scholarly journals Ring-opening carbonyl–olefin metathesis of norbornenes

2020 ◽  
Vol 11 (30) ◽  
pp. 7884-7895
Author(s):  
Janis Jermaks ◽  
Phong K. Quach ◽  
Zara M. Seibel ◽  
Julien Pomarole ◽  
Tristan H. Lambert
Keyword(s):  
Experimental Study ◽  
Olefin Metathesis ◽  
Ring Opening ◽  
Second Generation

A computational and experimental study has uncovered a second generation hydrazine that enables the catalytic ring-opening carbonyl–olefin metathesis of norbornenes.

Experimental Study on the Supercritical Water Co-Oxidation of Municiple Sludge with Methanol

2014 ◽  
Vol 651-653 ◽  
pp. 1341-1344
Author(s):  
Sheng Wen ◽  
Shu Zhong Wang ◽  
Yan Hui Li ◽  
Yu Zhen Wang
Keyword(s):  
Experimental Study ◽  
Acetic Acid ◽  
Co Oxidation ◽  
Ring Opening ◽  
Mass Fraction ◽  
Oxidation Process ◽  
Removal Rate ◽  
Methanol Solution ◽  
Cod Removal ◽  
Cod Removal Rate

The influence of methanol on the sludge removal rate of COD was investigated and the mechanism was obtained. The results show that the adding of methanol solution can improve the sludge COD removal rate, when the mass fraction of methanol is 5%, COD removal rate can be highly 99.98% compared 98.26% of that without methanol. The mechanism of co-oxidation is that methanol oxidation process can produce free radicals HO· and HO2·, they attack intermediate phenol and acetic acid, promote acetic acid to C-C bond fracture and ring-opening of phenol.

scholarly journals Ring-Opening Carbonyl-Olefin Metathesis of Norbornenes

2019 ◽  
Author(s):  
Janis Jermaks ◽  
Phong K. Quach ◽  
Zara M. Seibel ◽  
Julien Pomarole ◽  
Tristan Lambert
Keyword(s):  
Experimental Study ◽  
Theoretical Investigation ◽  
Olefin Metathesis ◽  
Ring Opening ◽  
Activation Barrier ◽  
Reaction Pathway ◽  
Next Generation ◽  
Methyl Group ◽  
Optimized Conditions ◽  
Hydrolysis Of

<div> <p>A computational and experimental study of the hydrazine-catalyzed ring-opening carbonyl-olefin metathesis of norbornenes is described. Detailed theoretical investigation of the energetic landscape for the full reaction pathway with six different hydrazines revealed several crucial aspects for the design of next-generation hydrazine catalysts. This study indicated that a [2.2.2]-bicyclic hydrazine should offer substantially increased reactivity versus the previously reported [2.2.1]-hydrazine due to a lowered activation barrier for the rate-determining cycloreversion step, a prediction which was verified experimentally. Optimized conditions for both cycloaddition and cycloreversion steps were identified, and a brief substrate scope study for each was conducted. A complication for catalysis was found to be the slow hydrolysis of the ring-opened hydrazonium intermediates, which were shown to suffer from a competitive and irreversible cycloaddition with a second equivalent of norbornene. This problem was overcome by the strategic incorporation of a bridgehead methyl group on the norbornene ring, leading to the first demonstrated catalytic carbonyl-olefin metathesis of norbornene rings.</p> </div>

Opposite Regiospecific Ring Opening of 2-(Cyanomethyl)aziridines by Hydrogen Bromide and Benzyl Bromide: Experimental Study and Theoretical Rationalization

2010 ◽  
Vol 75 (13) ◽  
pp. 4530-4541 ◽  
Author(s):  
Saron Catak ◽  
Matthias D’hooghe ◽  
Toon Verstraelen ◽  
Karen Hemelsoet ◽  
Andries Van Nieuwenhove ◽  
...  
Keyword(s):  
Experimental Study ◽  
Ring Opening ◽  
Hydrogen Bromide ◽  
Benzyl Bromide

scholarly journals Ring-Opening Carbonyl-Olefin Metathesis of Norbornenes

2019 ◽  
Author(s):  
Janis Jermaks ◽  
Phong K. Quach ◽  
Zara M. Seibel ◽  
Julien Pomarole ◽  
Tristan Lambert
Keyword(s):  
Experimental Study ◽  
Theoretical Investigation ◽  
Olefin Metathesis ◽  
Ring Opening ◽  
Activation Barrier ◽  
Reaction Pathway ◽  
Next Generation ◽  
Methyl Group ◽  
Optimized Conditions ◽  
Hydrolysis Of

<div> <p>A computational and experimental study of the hydrazine-catalyzed ring-opening carbonyl-olefin metathesis of norbornenes is described. Detailed theoretical investigation of the energetic landscape for the full reaction pathway with six different hydrazines revealed several crucial aspects for the design of next-generation hydrazine catalysts. This study indicated that a [2.2.2]-bicyclic hydrazine should offer substantially increased reactivity versus the previously reported [2.2.1]-hydrazine due to a lowered activation barrier for the rate-determining cycloreversion step, a prediction which was verified experimentally. Optimized conditions for both cycloaddition and cycloreversion steps were identified, and a brief substrate scope study for each was conducted. A complication for catalysis was found to be the slow hydrolysis of the ring-opened hydrazonium intermediates, which were shown to suffer from a competitive and irreversible cycloaddition with a second equivalent of norbornene. This problem was overcome by the strategic incorporation of a bridgehead methyl group on the norbornene ring, leading to the first demonstrated catalytic carbonyl-olefin metathesis of norbornene rings.</p> </div>

Experimental study on the restoration from a tilt-azimuth series for improvement in resolution

1995 ◽  
Vol 53 ◽  
pp. 636-637
Author(s):  
Norio Baba ◽  
Norihiko Ichise ◽  
Syunya Watanabe
Keyword(s):  
Experimental Study ◽  
Spherical Aberration ◽  
Incident Beam ◽  
Optical Parameters ◽  
Beam Tilting ◽  
Illumination Method ◽  
Restoration Method ◽  
Illumination Mode

The tilted beam illumination method is used to improve the resolution comparing with the axial illumination mode. Using this advantage, a restoration method of several tilted beam images covering the full azimuthal range was proposed by Saxton, and experimentally examined. To make this technique more reliable it seems that some practical problems still remain. In this report the restoration was attempted and the problems were considered. In our study, four problems were pointed out for the experiment of the restoration. (1) Accurate beam tilt adjustment to fit the incident beam to the coma-free axis for the symmetrical beam tilting over the full azimuthal range. (2) Accurate measurements of the optical parameters which are necessary to design the restoration filter. Even if the spherical aberration coefficient Cs is known with accuracy and the axial astigmatism is sufficiently compensated, at least the defocus value must be measured. (3) Accurate alignment of the tilt-azimuth series images.

Amino-functional polyethers: versatile, stimuli-responsive polymers

2020 ◽  
Vol 11 (24) ◽  
pp. 3940-3950 ◽  
Author(s):  
Patrick Verkoyen ◽  
Holger Frey
Keyword(s):  
Ring Opening ◽  
Review Article ◽  
Stimuli Responsive ◽  
New Class ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers

Amino-functional polyethers have emerged as a new class of “smart”, i.e. pH- and thermoresponsive materials. This review article summarizes the synthesis and applications of these materials, obtained from ring-opening of suitable epoxide monomers.

An Experimental Study of Some Properties of Stuttered Words

1962 ◽  
Vol 5 (4) ◽  
pp. 387-394 ◽  
Author(s):  
Bruce Quarrington ◽  
Jerome Conway ◽  
Nathan Siegel
Keyword(s):  
Experimental Study
Sign in / Sign up

Export Citation Format

Share Document