19853-09-9Relevant academic research and scientific papers
Carbon-13 chemical shift tensors in aromatic compounds. 3. Phenanthrene and triphenylene
Soderquist, Arien,Hughes, Craig D.,Horton, W. James,Facelli, Julio C.,Grant, David M.
, p. 2826 - 2832 (1992)
Measurements of the principal values of the 13C chemical shift tensor are presented for the three carbons in triphenylene and for three different α-carbons in phenanthrene. The measurements in triphenylene were made in natural abundance samples at room temperature, while the phenanthrene tensors were obtained from selectively labeled compounds (99% 13C) at low temperatures (～25 K). The principal values of the shift tensors were oriented in the molecular frame using ab initio LORG calculations. The steric compression at C4 in phenanthrene and in corresponding positions in triphenylene is manifested in a sizable upfield shift in the σ33 component relative to the corresponding σ33 values at C1 and C9 in phenanthrene. The upfield shift in σ33 is mainly responsible for the well-known upfield shift of the isotropic chemical shifts of such sterically perturbed carbons. In phenanthrene C9 exhibits a unique σ22 value reflecting the greater localization of π-electrons in the C9-C10 bond. This localization of the π-electrons at the C9-C10 bond in the central ring of phenanthrene also corresponds with the most likely ordering of electrons described by the various Kekule? structures in phenanthrene. The analysis of the 13C chemical shieldings of the bridgehead carbons in triphenylene provides significant experimental information on bonding between rings in polycyclic aromatic compounds. The results confirm that the electronic structure of triphenylene is best described by three fairly isolated benzene rings linked by C-C bonds of essentially single bond character. Similarly in phenanthrene, the bonding structure which correlates the shielding information may be characterized by the dominance of two benzene rings comprising the biphenyl moiety. A strong C9-C10 π-bond with only limited π-electron character in the C8a-C9 and C10-C10a bonds is indicated by both the experimental and theoretical results.
A facile synthesis of 3-(chloromethyl)-2-methyl-1,1'-biphenyl
Zhang, Lele,Cheng, Songbo,Hang,Defeng
, p. 3009 - 3011 (2019)
3-(Chloromethyl)-2-methyl-1,1′-biphenyl is a key intermediate for the preparation of bifenthrin, an insecticide which belongs to pyrethroid. The traditional synthetic process of 3-(chloromethyl)-2-methyl-1,1′-biphenyl is complicated and involves high-toxic and high-risk reagents such as thionyl chloride, lithium aluminum hydride and methyl iodide, which causes significant environmental problems and safety issues. Herein, a facile and efficient synthesis process of 3-(chloromethyl)-2- methyl-1,1′-biphenyl was developed. The synthetic process is shortened from 6 steps to only 4 steps and avoids the use of high-toxic and high-risk reagents. Moreover, 3-(chloromethyl)-2-methyl-1,1′-biphenyl can be obtained by simple purification process in high yield (73.9 %). Compared with the traditional synthetic process, the synthetic process of 3-(chloromethyl)-2-methyl-1,1′-biphenyl reported here is more environmental friendly and efficient.
Binuclear metallocene compound, preparation method and applications thereof
-
Paragraph 0077; 0120-0122; 0128-0131, (2020/05/30)
The invention relates to the field of olefin polymerization, and discloses a binuclear metallocene compound, a preparation method and applications thereof, wherein the binuclear metallocene compound has a structure represented by a formula (1). When the binuclear metallocene compound is applied to olefin polymerization as a catalyst component, good catalytic activity can be effectively provided, and a polyolefin product with improved isotacticity is prepared.
Thiourea-Catalyzed C?F Bond Activation: Amination of Benzylic Fluorides
Houle, Camille,Savoie, Paul R.,Davies, Clotilde,Jardel, Damien,Champagne, Pier Alexandre,Bibal, Brigitte,Paquin, Jean-Fran?ois
supporting information, p. 10620 - 10625 (2020/07/24)
We describe the first thiourea-catalyzed C?F bond activation. The use of a thiourea catalyst and Ti(OiPr)4 as a fluoride scavenger allows the amination of benzylic fluorides to proceed in moderate to excellent yields. Preliminary results with S- and O-based nucleophiles are also presented. DFT calculations reveal the importance of hydrogen bonds between the catalyst and the fluorine atom of the substrate to lower the activation energy during the transition state.
Method for preparing N,N-dimethyl-1-alkyl diphenylmethylamine
-
Paragraph 0042-0046; 0061-0063; 0068-0070, (2019/01/21)
The invention discloses a method for preparing N,N-dimethyl-1-alkyl diphenylmethylamine and relates to the field of fine chemical engineering. The method disclosed by the invention comprises the following steps: taking waste alkyl biphenyl recovered in the conventional process as a raw material, carrying out a free radical reaction between the raw material and a halogenating reagent in the presence of a catalyst so as to obtain halogenated alkyl biphenyl; reacting the halogenated alkyl biphenyl and organic alkali to obtain a quaternary ammonium salt; and finally, performing low temperature inversion under liquid ammonia conditions, thereby obtaining N,N-dimethyl-1-(2-methyl-[1,1'-biphenyl]-3-yl) methylamine. Usage of a high-risk reagent lithium aluminum hydride and a strong carcinogen iodomethane can be avoided in the preparation process of the N,N-dimethyl-1-(2-methyl-[1,1'-biphenyl]-3-yl) methylamine, harm to the human body is eliminated, production of three wastes is reduced, the environmental pollution is avoided, and the method is safe and environmental-friendly.
Containing 4 - imidazolyl of glutaminyl cyclase inhibitor preparation method and application of (by machine translation)
-
Paragraph 0043; 0045-0047, (2019/02/19)
The invention discloses a containing 4 - imidazolyl of glutaminyl cyclase inhibitor preparation method and application, wherein the method includes the steps of: in order to has the bromine substituent and R1 B unit of raw materials and with boron acid radical and R2 C unit raw materials of starting, by the Suzuki coupling reaction, preparation B unit and C unit coupled biphenyl intermediate; to B unit and C unit coupled biphenyl intermediate and 2 - (1 H - imidazole - 4 - yl) ethylamine as a raw material, by the SN2 The reaction preparation obtained based on 4 - imidazolyl pharmocology compound. Preparation method of this invention, its only need to Suzuki coupling, SN2 reaction two-step to be completed, the process of the invention route is simple and feasible, high yield, is more suitable for large-scale preparation; and the present invention obtained in the preparation method based on 4 - imidazolyl of glutaminyl cyclase inhibitor has high activity, can be widely used for high-efficiency QC inhibitor the development of new drugs, AD, tumor, rheumatic arthritis QC specific high expression related diseases, early diagnosis and diagnostic kit and the development of. (by machine translation)
MALONONITRILE OXIME ETHER COMPOUND AND USE THEREOF
-
Paragraph 0086; 0087, (2019/01/04)
Disclosed is a malononitrile oxime ether compound having a novel structure as shown in the general formula I. Respective substituents in the general formula I as defined in the specification. The compound of the general formula I exhibits an excellent microbicidal activity, and can effectively prevent and treat plant diseases caused by bacteria and fungi. Also provided is a use of the compound of the general formula I as a microbicide in the agricultural and other fields.
Glutaminyl cyclase inhibitor containing 4-imidazolyl group
-
Paragraph 0034; 0036; 0037; 0038, (2019/01/06)
The invention discloses a glutaminyl cyclase inhibitor containing a 4-imidazolyl group. The structural formula of the glutaminyl cyclase inhibitor containing the 4-imidazolyl group is shown in the description. The glutaminyl cyclase inhibitor containing a 4-imidazolyl group is designed according to a crystal structure at the active center of a target enzyme protein, so the structure diversity of amolecular key pharmacophore is further expanded, and the QC inhibition activity is high.
Synthesis of Fluorenes Starting from 2-Iodobiphenyls and CH2Br2 through Palladium-Catalyzed Dual C-C Bond Formation
Shi, Guangfa,Chen, Dushen,Jiang, Hang,Zhang, Yu,Zhang, Yanghui
supporting information, p. 2958 - 2961 (2016/07/06)
A facile and efficient approach is developed for the synthesis of fluorene and its derivatives starting from 2-iodobiphenyls and CH2Br2. A range of fluorene derivatives can be synthesized under relatively mild conditions. The reaction proceeds via a tandem palladium-catalyzed dual C-C bond formation sequence through the key dibenzopalladacyclopentadiene intermediates, which are obtained from 2-iodobiphenyls through palladium-catalyzed C-H activation.
Gold-catalyzed 6-exo-dig cycloisomerization: A versatile approach to functionalized phenanthrenes
Shu, Chao,Li, Long,Chen, Cheng-Bin,Shen, Hong-Cheng,Ye, Long-Wu
supporting information, p. 1525 - 1529 (2014/06/09)
A novel gold-catalyzed 6-exo-dig cycloisomerization of o-propargylbiaryls has been developed that provides ready access to functionalized phenanthrenes in largely good to excellent yields. Notable features of this method are readily available starting materials, mild reaction conditions, and broad substrate scope. Golden cat: A novel gold-catalyzed 6-exo-dig cycloisomerization of o-propargylbiaryls has been developed that provides ready access to functionalized phenanthrenes in largely good to excellent yields. Notable features of this method are readily available starting materials, mild reaction conditions, and broad substrate scope.
