Substituent Effects on Stoichiometric and Catalytic Cleavage of Carbon–Nitrogen Bonds in Aniline Derivatives by Ruthenium–Phosphine Complexes

2013 ◽  
Vol 32 (2) ◽  
pp. 682-690 ◽  
Author(s):  
Tetsuro Koreeda ◽  
Takuya Kochi ◽  
Fumitoshi Kakiuchi
Keyword(s):  
Substituent Effects ◽  
Aniline Derivatives ◽  
Phosphine Complexes ◽  
Catalytic Cleavage ◽  
Nitrogen Bonds

Highly Efficient Synthesis of Oxindole Derivatives Via Catalytic Intramolecular C-H Insertion Reactions of Diazoamides

2020 ◽  
Vol 840 ◽  
pp. 251-256 ◽  
Author(s):  
Phan Thi Thanh Nga ◽  
Masaya Tone ◽  
Hayato Inoue ◽  
Kazutaka Shibatomi ◽  
Seiji Iwasa
Keyword(s):  
Aromatic Ring ◽  
Substituent Effects ◽  
Efficient Synthesis ◽  
Insertion Reactions ◽  
Aniline Derivatives ◽  
Highly Efficient ◽  
High Yields

Oxindole derivatives were efficiently synthesized from diazoamides derived from aniline derivatives in the presence of a Ru(II)-Pheox catalyst. Ru(II)-Pheox was found to be one of the most efficient catalysts so far for the synthesis of oxindole derivatives from the diazoamides in high yields (up to 99%) with high regioselectivity. Furthermore, the reaction was rapid and no substituent effects on the aromatic ring.

Homogeneous Catalytic Cleavage of Saturated Carbon-Nitrogen Bonds

1986 ◽  
Vol 27 (3) ◽  
pp. 267-275 ◽  
Author(s):  
Y. Shvo ◽  
M. Abed ◽  
Y. Blum ◽  
R.M. Laine
Keyword(s):  
Catalytic Cleavage ◽  
Nitrogen Bonds

Reaction of 4-Chloro-3,5-Dinitrobenzotrifluoride with Aniline Derivatives. Substituent Effects

2007 ◽  
Vol 2007 (9) ◽  
pp. 509-512 ◽  
Author(s):  
Hamida O.M. Al-Howsaway ◽  
Magda F. Fathalla ◽  
Ali A. El-Bardan ◽  
Ezzat A. Hamed
Keyword(s):  
Hydrogen Bond ◽  
Transition State ◽  
Positive Charge ◽  
Bond Formation ◽  
Substituent Effects ◽  
Nmr Studies ◽  
H Nmr ◽  
Aniline Derivatives ◽  
Elimination Mechanism ◽  
Intramolecular Hydrogen

N-(2,6-Dinitro-4-trifluoromethylphenyl)aniline derivatives were prepared by anilino-dechlorination of 4-chloro-3, 5-dinitrobenzotrifluoride. IR, UV and 1H NMR studies suggested an intramolecular hydrogen bond between the amino hydrogen and one o-nitro group. An addition-elimination mechanism was suggested based on the second-order kinetics and the dependence of rates on the nature and the position of the substituent in the aniline ring, as well as the high negative values of ρ(-3.14, −3.16, −3.01). Such values indicate a positive charge on the aniline nitrogen in the transition state and that the rate is affected by the polar effect of the substituent. The β value (0.85 at 30°C) indicates an appreciable degree of bond formation in the transition state.

Substituent effects and solvents

1992 ◽  
Vol 89 ◽  
pp. 1567-1571
Author(s):  
O Pytela ◽  
M Ludwig
Keyword(s):  
Substituent Effects

Substituent Effects on the Thermal Decomposition of Phosphate Esters on Ferrous Surfaces

2019 ◽  
Author(s):  
James Ewen ◽  
Carlos Ayestaran Latorre ◽  
Arash Khajeh ◽  
Joshua Moore ◽  
Joseph Remias ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Film Formation ◽  
Substituent Effects ◽  
Vapour Phase ◽  
Industrial Applications ◽  
Phosphate Esters ◽  
Antiwear Additives ◽  
Formation Mechanisms ◽  
Phosphate Ester ◽  
Wide Range

<p>Phosphate esters have a wide range of industrial applications, for example in tribology where they are used as vapour phase lubricants and antiwear additives. To rationally design phosphate esters with improved tribological performance, an atomic-level understanding of their film formation mechanisms is required. One important aspect is the thermal decomposition of phosphate esters on steel surfaces, since this initiates film formation. In this study, ReaxFF molecular dynamics simulations are used to study the thermal decomposition of phosphate esters with different substituents on several ferrous surfaces. On Fe<sub>3</sub>O<sub>4</sub>(001) and α-Fe(110), chemisorption interactions between the phosphate esters and the surfaces occur even at room temperature, and the number of molecule-surface bonds increases as the temperature is increased from 300 to 1000 K. Conversely, on hydroxylated, amorphous Fe<sub>3</sub>O<sub>4</sub>, most of the molecules are physisorbed, even at high temperature. Thermal decomposition rates were much higher on Fe<sub>3</sub>O<sub>4</sub>(001) and particularly α-Fe(110) compared to hydroxylated, amorphous Fe<sub>3</sub>O<sub>4</sub>. This suggests that water passivates ferrous surfaces and inhibits phosphate ester chemisorption, decomposition, and ultimately film formation. On Fe<sub>3</sub>O<sub>4</sub>(001), thermal decomposition proceeds mainly through C-O cleavage (to form surface alkyl and aryl groups) and C-H cleavage (to form surface hydroxyls). The onset temperature for C-O cleavage on Fe<sub>3</sub>O<sub>4</sub>(001) increases in the order: tertiary alkyl < secondary alkyl < primary linear alkyl ≈ primary branched alkyl < aryl. This order is in agreement with experimental observations for the thermal stability of antiwear additives with similar substituents. The results highlight surface and substituent effects on the thermal decomposition of phosphate esters which should be helpful for the design of new molecules with improved performance.</p>

The Nature of S-N Bonding in Sulfonamides and Related Compounds: Insights into π-Bonding Contributions from Sulfur K-Edge XAS

2020 ◽  
Author(s):  
Tulin Okbinoglu ◽  
Pierre Kennepohl
Keyword(s):  
Density Functional ◽  
Chemical Properties ◽  
Functional Theory ◽  
Rotational Barriers ◽  
Td Dft ◽  
Nitrogen Bonds ◽  
X Ray Absorption ◽  
Related Compounds ◽  
And Chemical Properties

Molecules containing sulfur-nitrogen bonds, like sulfonamides, have long been of interest due to their many uses and chemical properties. Understanding the factors that cause sulfonamide reactivity is important, yet their continues to be controversy regarding the relevance of S-N π bonding in describing these species. In this paper, we use sulfur K-edge x-ray absorption spectroscopy (XAS) in conjunction with density functional theory (DFT) to explore the role of S<sub>3p</sub> contributions to π-bonding in sulfonamides, sulfinamides and sulfenamides. We explore the nature of electron distribution of the sulfur atom and its nearest neighbors and extend the scope to explore the effects on rotational barriers along the sulfur-nitrogen axis. The experimental XAS data together with TD-DFT calculations confirm that sulfonamides, and the other sulfinated amides in this series, have essentially no S-N π bonding involving S<sub>3p</sub> contributions and that electron repulsion and is the dominant force that affect rotational barriers.

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