99827-46-0Relevant articles and documents
Chiral Ligands in Hypervalent Iodine Compounds: Synthesis and Structures of Binaphthyl-Based λ3-Iodanes
Zhang, Huaiyuan,Cormanich, Rodrigo A.,Wirth, Thomas
, (2021/12/22)
Several novel binaphthyl-based chiral hypervalent iodine(III) reagents have been prepared and structurally analysed. Various asymmetric oxidative reactions were applied to evaluate the reactivities and stereoselectivities of those reagents. Moderate to excellent yields were observed; however, very low stereoselectivities were obtained. NMR experiments indicated that these reagents are very easily hydrolysed in either chloroform or DMSO solvents leading to the limited stereoselectivities. It is concluded that the use of chiral ligands is an unsuccessful way to prepare efficient stereoselective iodine(III) reagents.
TRANSITION METAL COMPOUND FOR OLEFIN POLYMERIZATION CATALYST, OLEFIN POLYMERIZATION CATALYST COMPRISING SAME AND POLYOLEFIN POLYMERIZED USING SAME
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Paragraph 0050-0051, (2021/06/11)
Provided is a transition metal compound, represented by chemical formula 1, for an olefin polymerization catalyst. The details of chemical formula 1 are the same as those defined in the specification.
Synthesis method of axially chiral dinaphthalene ligand precursor (s)-2,2'-dinaphthyl-1,1'-dicarboxylic acid
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, (2016/10/10)
The invention relates to the technical field of bromination, hydrolysis, oxidation and coupling reaction in organic synthesis, particularly a synthesis method of an axially chiral dinaphthalene ligand precursor (s)-2,2'-dinaphthyl-1,1'-dicarboxylic acid. The method comprises the following steps: synthesizing a compound 1-bromo-2-methylnaphthalene from an initial raw material 2-bromomethylnaphthalene, carrying out bromination, hydrolysis and oxidation on the 1-bromo-2-methylnaphthalene to obtain 1-bromo-2-naphthoic acid, generating an ester under the actions of methanol and thionyl chloride, protecting the carboxyl group, carrying out Ullmann reaction under the action of copper powder to perform coupling, carrying out hydrolysis to obtain 2,2'-dinaphthyl-1,1'-dicarboxylic acid, and finally, resolving to obtain the (s)-2,2'-dinaphthyl-1,1'-dicarboxylic acid. The method is simple to operate, and has the advantages of higher yield and favorable economical efficiency.
Practical synthesis of axially chiral dicarboxylates via Pd-catalyzed external-CO-free carbonylation
Konishi, Hideyuki,Hoshino, Fumika,Manabe, Kei
, p. 1438 - 1441 (2016/10/09)
We have developed a safe and practical synthetic method for preparing axially chiral diphenyl dicarboxylates using Pd- catalyzed external-CO-free carbonylation with phenyl formate as a CO surrogate. Optimized conditions consisted of axially chiral [1,1′-binaphthalene]-2,2′-diyl ditriflate and its congeners, each easily prepared from commercially available enantiomerically pure diols, Pd(OAc)2, 1,3-bis(diphenylphosphino)-propane, ethyldiisopropylamine, and no solvent. To demonstrate the potential utility of these products, this method was conducted on gram-scale and the phenyl ester products were converted to other useful compounds, and both processes were carried out without difficulty.
Design and synthesis of new stable fluorenyl-based radicals
Tian, Yi,Uchida, Kazuyuki,Kurata, Hiroyuki,Hirao, Yasukazu,Nishiuchi, Tomohiko,Kubo, Takashi
, p. 12784 - 12793 (2015/02/19)
Organic neutral radicals have long fascinated chemists with a fundamental understanding of structure-reactivity relationships in organic reactions and with applications as new functional materials. However, the elusive nature of these radicals makes the synthesis, isolation, and characterization very challenging. In this work, the synthesis of three long-lived, fluorenyl-based radicals are reported. The geometry and electronic structures of these radicals were systematically investigated with a combination of various experimental methods, besides density functional theory (DFT) calculations, which include X-ray crystallographic analysis, electron spin resonance (ESR), electron nuclear double resonance (ENDOR), cyclic voltammetry, and UV-vis-NIR measurements. Their half-life periods (τ1/2) in air-saturated solution under ambient conditions were also determined. Surprisingly, all three radicals showed remarkable stabilities: τ1/2 = 7, 3.5, and 43 days.
In situ generation of hydroperoxide by oxidation of benzhydrols to benzophenones using sodium hydride under oxygen atmosphere: Use for the oxidative cleavage of cyclic 1,2-diketones to dicarboxylic acids
Kang, Sunhae,Lee, Soyoung,Jeon, Minju,Kim, Sun Min,Kim, Young Sug,Han, Hogyu,Yang, Jung Woon
, p. 373 - 376 (2013/02/23)
A facile oxidative cleavage of cyclic 1,2-diketones 1 to dicarboxylic acids 3 with hydroperoxide generated in situ has been developed. In situ generation of hydroperoxide was effected by the oxidation of 4,4′-dichlorobenzhydrol 2f to 4,4′-dichlorobenzophenone 4f using sodium hydride under oxygen atmosphere.
DIBENZO[C,G]FLUORENE COMPOUND AND ORGANIC LIGHT-EMITTING DEVICE USING SAME
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Page/Page column 11; 40-41, (2010/06/11)
An organic light-emitting device is provided which efficiently emits light with high brightness and has durability. The organic light-emitting device includes a dibenzo[c,g]fluorene compound having two dibenzo[c,g]fluorene skeletons, and has an organic compound layer containing the dibenzo[c,g]fluorene compound.
DIBENZO[c,g]FLUORENE COMPOUND AND AN ORGANIC LIGHT-EMITTING DEVICE USING THE SAME
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Page/Page column 55-56, (2009/12/23)
An organic light-emitting device which has high emission efficiency and high durability even at low drive voltage is provided. An organic light-emitting device including an anode, a cathode, and an organic compound layer which is interposed between the anode and the cathode, wherein the organic compound layer include at least one dibenzo[c,g]fluorene compound represented by the following General Formula (1).
Embedding an allylmetal dimer in a chiral cavity: The unprecedented stereoselectivity of a twofold Wittig [1,2]-rearrangement
Schlosser, Manfred,Bailly, Frederic
, p. 16042 - 16043 (2007/10/03)
After α,α'-dimetalation, both 2,2′-diallyloxy-1,1′-binaphthyl and 2,2′-di-2-methylallyloxy-1,1′-binaphthyl undergo the Wittig rearrangement with perfect diastereoselectivity. When racemic 1,1′-binaphthyl-2,2′-diol ("BINOL") is used as the starting material, it gives rise to a 1:1 mixture of antipodal stereoisomers, whereas enantiomerically pure (M)-2,2′-diallyloxy-1,1′-binaphthyl affords (M)-(S,S)-1,1-(1,1′-binaphthyl-2,2′-diyl)bis(2-propen-1-ol) as the sole product. The (M)-(S,S)/(P)-(R,R) mixture resulting from the rearrangement of racemic 2,2′-diallyloxy-1,1′-binaphthyl can be effectively subjected to a kinetic racemate resolution by applying the Sharpless-Katsuki asymmetric epoxidation. The single-sided Wittig rearrangement of 2-allyloxy-2′-propyloxy-1,1′-binaphthyl proceeds without any diastereoselectivity as this substrate can only be monometalated and hence is incapable of intramolecular aggregate formation which is instrumental for the observed stereoselectivity. Copyright
Practical synthetic protocols of enantiopure 1,1′-binaphthyl-2, 2′-dicarboxylic acid and 2,2′-dicyano-1,1′-binaphthyl starting from optically active dibromide precursor
Hoshi, Takashi,Nozawa, Eiji,Katano, Masayoshi,Suzuki, Toshio,Hagiwara, Hisahiro
, p. 3485 - 3487 (2007/10/03)
Dilithiation of optically active 2,2′-dibromo-1,1 ′-binaphthyl 2 with t-BuLi followed by carboxylation of the resulting dilithio-intermediate 3 with CO2 gave optically active 1,1′-binaphthyl-2,2′-dicarboxylic acid 1, which was further transformed to its dicyano derivative 4. Both of these transformations were carried out in a one-pot operation and the products were obtained in excellent yields with no observable racemization.
