Sterically Facilitated Intramolecular Nucleophilic NMe2 Group Substitution in the Synthesis of Fused Isoxazoles: Theoretical Study

The influence of steric repulsion between the NMe2 group and a second ortho-(peri-)substituent in the series of 1-dimethylaminonaphthalene and N,N-dimethylanilene ortho-oximes on the ease of the NMe2 group’s intramolecular nucleophilic substitution is studied. Possible reaction intermediates for three mechanisms are calculated (ωB97xd/def-2-TZVP), and their free Gibbs energies are compared to model reaction profiles. Supporting experiments have proved the absence of studied reactivity in the case of simple 2-dimethylaminobenzaldoxime, which allowed us to establish reactivity limits. The significant facilitation of NMe2 group displacement in the presence of bulky substituents is demonstrated. The possibility of fused isoxazoles synthesis via the intramolecular nucleophilic substitution of a protonated NMe2 group in the aniline and naphthalene series is predicted.

C–H Functionalization Strategies in the Naphthalene Series: Site Selections and Functional Diversity

Naphthalene is certainly not a common arene. In contrast to benzene, the bicyclic feature of naphthalene offers multiple differentiable positions and thus a broad diversity of substitution patterns. Naphthalene is a central building block for the construction of elaborated polycyclic architectures with applications in broad domains such as life and materials sciences. As a result, C–H functionalization strategies specially designed for naphthalene substrates have become essential to install valuable substituents on one or both rings towards polysubstituted naphthalenes. This short review provides a focus on uncommon substitution patterns; however, classical ortho C–H activation is not covered.1 Introduction2 C–H Functionalization Using a Directing Group Located at Position 12.1 Functionalization on the Ring Bearing the DG: 1,3-Substitution Pattern2.2 Functionalization on the Ring Bearing the DG: 1,4-Substitution Pattern2.3 Functionalization on the Neighboring Ring: 1,6-, 1,7- and 1,8-Substitution Patterns3 C–H Functionalization Using a Directing Group Located at Position 23.1 Functionalization on the Ring Bearing the DG: 2,4- and 2,1-Substitution Patterns3.2 Miscellaneous Substitution Patterns4 Bis C–H Functionalization4.1 Symmetrical Bisfunctionalization: 1,2,8-Substitution Pattern4.2 Symmetrical Bisfunctionalization: 2,3,1-Substitution Pattern4.2 Unsymmetrical Bisfunctionalization: 2,3,1-Substitution Pattern4.3 Symmetrical Bisfunctionalization: 2,4,8-Substitution Pattern5 Conclusion and Outlook

Biodestruction of Petroleum Hydrocarbons

Biodegradation of light and high-viscosity oils by hydrocarbon-oxidizing microflora has been studied. Microflora was isolated from the formation waters recovered from West Siberian and “White Tiger” (Vietnam) oil fields. To activate microorganisms one used the solution of IKhN-KA system containing a multi-component nitrogenous nutrient substrate. Under the condition of active development of microorganisms during 5 days of biodegradation the concentration of n-alkanes C10-C32 in light oils decreased by 70-85 % and that of viscous oil – by 86-93 %. Destruction of mono-aromatic compounds accounted for 55-65 % and that of aromatic compounds of naphthalene series – 70-90 %. The content of methyl- and<br />trimethyl phenanthrenes decreased 3 times. Therefore a degree of oil destruction depends on nutrient substrates, which stimulate biochemical processes of vital activity.

Research on the Effects of Admixtures on the Physical Properties of Titanium Gypsum

Through to join in processing of titanium gypsum naphthalene series water reducing agent and sodium sulfate, study the effect of admixtures on the physical properties of titanium gypsum and mechanism analysis, and to determine the optimum content of admixtures. Research shows that when the content of naphthalene series water reducing agent was 3% water reducing effect is best, the titanium gypsum sample standard consistency water consumption is 126%,2h flexural strength was 1.06MPa, 2h compressive strength was 1.97MPa, absolutely dry flexural strength was 2.21MPa and absolutely dry compressive strength was 2.76 MPa. When the dosage of sodium sulfate is 1.5%, titanium gypsum physical performance is best,initial setting time and final setting time of 8 min and 10 min respectively,2h flexural strength was 1.35MPa, 2h compressive strength was 2.42MPa, absolutely dry flexural strength was 2.43MPa and absolutely dry compressive strength was 3.32 MPa.

Air Entraining Agent Effects Research on Concrete Performance

In order to improve concrete freezing-thawing resisting ability in Inner Mongolia region, adding air entraining agent is one effective measure. Because triterpenoid saponins air-entraining agent have a good applicability for local raw material, it makes concrete slump obvious increase with different water cement ratio, but the range ability first increases then decreases, the 3d, 7d and 28d compressive strength influence are the same to the slump influence, which can effectively improve concrete freezing-thawing resisting cycle times, and mixing with naphthalene series water reducing agent applies to mix small water cement concrete, and high strength grade.

Application of Water Reducing Agent in Concrete of Engineering Materials

In this paper, in order to discuss the compatibility of cement and different kinds of water reducers, three kinds of water reducers which were selected to use in the mix proportion of Jing Shi Special Passenger Line were chosen. Tests of cement paste and concrete of Portland cement (P∙O42.5) were carried out under different temperature, because this kind of cement is widely used in the current projects. Results show that polycarboxylic series water reducer, compared with naphthalene series water reducer, have properties of high compatibility, low mixing amount, high water-reducing rate and low slump loss of concrete. So it is more suitable to prepare concrete with fly ash and more beneficial to increase the strength of concrete.

Experimental Study on Quality Control of Moderate-Strength Commercial Concrete

For the quality control of commercial concrete, it is important to choose correct raw- material and mixture ratio. C40 and C50 concrete were prepared in dry and cold climate environment, using local raw materials and a large amount of fly ash. Specific researches were made about different kinds and dosage of superplasticizers on the slump of concrete, slump loss and the intensity of the impact. The results show that naphthalene series superplasticizer JK-2 and 30% of fly ash can ensure that slump of the mixture concrete reach more than 180mm, slump loss is less than 30mm in an hour, strength of hardened paste will not be reduced, and concrete can be prepared with low costs.