176504-70-4Relevant academic research and scientific papers
Design of spontaneously blinking fluorophores for live-cell super-resolution imaging based on quantum-chemical calculations
Tachibana, Ryo,Kamiya, Mako,Morozumi, Akihiko,Miyazaki, Yoshiyuki,Fujioka, Hiroyoshi,Nanjo, Aika,Kojima, Ryosuke,Komatsu, Toru,Ueno, Tasuku,Hanaoka, Kenjiro,Yoshihara, Toshitada,Tobita, Seiji,Urano, Yasuteru
supporting information, p. 13173 - 13176 (2020/11/09)
Spontaneously blinking fluorophores are powerful tools for live-cell super-resolution imaging under physiological conditions. Here we show that quantum-chemical calculations can predict key parameters for fluorophore design. We applied this methodology to
Preparation method and application of topramezone
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Paragraph 0038-0043, (2020/08/02)
The invention discloses a preparation method and application of topramezone, and the preparation method comprises the following steps: taking 2-methylbenzaldehyde, a bromination reagent, a catalyst, hydroxylamine hydrochloride, an alkali, ethylene gas, a sulfonylation reagent and a preset solvent as reaction raw materials, and preparing 3-[3-bromo-methyl-6-(methylsulfonyl) phenyl]-4, 5-dihydroisoxazole through a first reaction process; taking diethyl malonate, triethyl orthoformate, nickel sulfate, monobasic saturated carboxylic acid, methylhydrazine, a hydrocarbon solvent, an ethanol solutionand hydrochloric acid as reaction raw materials, and carrying out a second reaction process to prepare 1-methyl-5-hydroxypyrazole; and taking the 3-[3-bromo-methyl-6-(methylsulfonyl) phenyl]-4, 5 dihydroisoxazole,-1-methyl-5-hydroxypyrazole, triethylamine, potassium carbonate, palladium chloride, triphenylphosphine, 1, 4-dioxane, water, a saturated NaHCO3 solution and a hydrochloric acid solutionas reaction raw materials, and carrying out a third reaction process to prepare the topramezone. The problems that a sulfur-containing intermediate can emit odor and the raw materials are difficult to obtain in the existing process are solved.
Palladium-catalyzed ortho-C(sp2)[sbnd]H bromination of benzaldehydes via a monodentate transient directing group strategy
Yong, Qiyun,Sun, Bing,Zhang, Fang-Lin
supporting information, (2019/11/03)
A facile and efficient monodentate transient directing group strategy was developed to enable the palladium-catalyzed ortho-C(sp2)[sbnd]H bromination of benzaldehydes. A broad scope of benzaldehydes were transformed into the desired products by employing 2-amino-5-chlorobenzotrifluoride as a monodentate transient directing group, demonstrating good functional group tolerance. Mild reaction conditions and no requirement for a silver salt are also features of this strategy.
Rh(III)-Catalyzed Phosphine Oxide Migration Reactions: Selective Synthesis of 3-Phosphinoylindoles
Wang, Chun-Hai,Yang, Shang-Dong
supporting information, p. 2401 - 2404 (2018/09/10)
3-Phosphinoylindoles are important components of biological active natural products and materials in pharmaceuticals. Herein, a new approach for the synthesis of 3-phosphinoylindoles has been established by a Rh(III)-catalyzed cyclization from readily acc
Chemoselective Reduction of Sterically Demanding N,N-Diisopropylamides to Aldehydes
Xiao, Peihong,Tang, Zhixing,Wang, Kai,Chen, Hua,Guo, Qianyou,Chu, Yang,Gao, Lu,Song, Zhenlei
, p. 1687 - 1700 (2018/02/23)
A sequential one-pot process for chemoselectively reducing sterically demanding N,N-diisopropylamides to aldehydes has been developed. In this reaction, amides are activated with EtOTf to form imidates, which are reduced with LiAlH(OR)3 [R = t-Bu, Et] to give aldehydes by hydrolysis of the resulting hemiaminals. The non-nucleophilic base 2,6-DTBMP remarkably improves reaction efficiency. The combination of EtOTf/2,6-DTBMP and LiAlH(O-t-Bu)3 was found to be optimal for reducing alkyl, alkenyl, alkynyl, and 2-monosubstituted aryl N,N-diisopropylamides. In contrast, EtOTf and LiAlH(OEt)3 in the absence of base were found to be optimal for reducing extremely sterically demanding 2,6-disubstituted N,N-diisopropylbenzamides. The reaction tolerates various reducible functional groups, including aldehyde and ketone. 1H NMR studies confirmed the formation of imidates stable in water. The synthetic usefulness of this methodology was demonstrated with N,N-diisopropylamide-directed ortho-metalation and C-H bond activation.
Diverse ortho-C(sp2)-H functionalization of benzaldehydes using transient directing groups
Liu, Xi-Hai,Park, Hojoon,Hu, Jun-Hao,Hu, Yan,Zhang, Qun-Liang,Wang, Bao-Long,Sun, Bing,Yeung, Kap-Sun,Zhang, Fang-Lin,Yu, Jin-Quan
supporting information, p. 888 - 896 (2017/05/16)
Pd-catalyzed C-H functionalizations promoted by transient directing groups remain largely limited to C-H arylation only. Herein, we report a diverse set of ortho-C(sp2)-H functionalizations of benzaldehyde substrates using the transient directing group strategy. Without installing any auxiliary directing group, Pd(II)-catalyzed C-H arylation, chlorination, bromination, and Ir(III)-catalyzed amidation, could be achieved on benzaldehyde substrates. The transient directing groups formed in situ via imine linkage can override other coordinating functional groups capable of directing C-H activation or catalyst poisoning, significantly expanding the scope for metal-catalyzed C-H functionalization of benzaldehydes. The utility of this approach is demonstrated through multiple applications, including late-stage diversification of a drug analogue.
Selective ortho -bromination of substituted benzaldoximes using Pd-catalyzed C-H activation: Application to the synthesis of substituted 2-bromobenzaldehydes
Dubost, Emmanuelle,Fossey, Christine,Cailly, Thomas,Rault, Sylvain,Fabis, Frederic
, p. 6414 - 6420 (2011/09/16)
Substituted 2-bromobenzaldehydes were synthesized from benzaldehydes using a three-step sequence involving a selective palladium-catalyzed ortho-bromination as the key step. O-Methyloxime serves as a directing group in this reaction. A rapid deprotection of substituted 2-bromobenzaldoximes afforded substituted 2-bromobenzaldehydes with good overall yields.
New cyclopentadienyl, indenyl or fluorenyl substituted phosphine compounds and their use in catalytic reactions
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Page/Page column 35-36, (2008/06/13)
The invention is directed to a phosphine compound represented by general formula (1) wherein R' and R" independently are selected from alkyl, cycloalkyl and 2-furyl radicals, or R' and R" are joined together to form with the phosphorous atom a carbon-phosphorous monocycle comprising at least 3 carbon atoms or a carbon-phosphorous bicycle; the alkyl radicals, cycloalkyl radicals, and carbon-phosphorous monocycle being unsubstituted or substituted by at least one radical selected from the group of alkyl, cycloalkyl, aryl, alkoxy, and aryloxy radicals; Cps is a partially substituted or completely substituted cyclopentadien-1-yl group, including substitutions resulting in a fused ring system, and wherein a substitution at the 1-position of the cyclopentadien-1-yl group is mandatory when the cyclopentadien-1-yl group is not part of a fused ring system or is part of an indenyl group. Also claimed is the use of these phosphines as ligands in catalytic reactions and the preparation of these phosphines.
9-Fluorenylphosphines for the Pd-catalyzed Sonogashira, Suzuki, and Buchwald-Hartwig coupling reactions in organic solvents and water
Fleckenstein, Christoph A.,Plenio, Herbert
, p. 2701 - 2716 (2008/03/14)
The lithiation/alkylation of fluorene leads to various 9-alkyl-fluorenes (alkyl = Me. Et, /Pr, -Pr. -C18H25) in > 95% yields, for which lithiation and reaction with R2PCl (R = Cy, iPr, tBu) generates 9-alkyl, 9-PR2fluorenes which constitute electron-rich and bulky phosphine ligands. The in-situ-formed palladium-phosphinc complexes ([Na2PdCl4], phosphonium salt, base, substrates) were tested in the Sonogashira. Suzuki, and Buchwald-Hartwig reactions of aryl chlorides and aryl bromides in organic solvents. The Sonogashira coupling of aryl chlorides at 100-120°C leads to >90% yields with 1 mol % of Pd catalyst. The Suzuki coupling of aryl chlorides typically requires 0.05 mol % of Pd catalyst at 100°C in dioxane for quantitative product formation. To carry out "green" cross-coupling reactions in water, 9-ethylfluorenyldicyclohexylphosphine was reacted in sulphuric acid to generate the respective 2-sulfonated phosphonium salt. The Suzuki coupling of activated aryl chlorides by using this water-soluble catalyst requires only 0.01 mol% of Pd catalyst, while a wide range of aryl chlorides can be quantitatively converted into the respective coupling products by using 0.1-0.5 mol % of catalyst in pure water at 100°C. Difficult substrate combinations, such as naphthylboronic acid or 3-pyridylboronic acid and aryl chlorides are coupled at 100°C by using 0.1-0.5 mol % of catalyst in pure water to obtain the respective N-heterocycles in quantitative yields. The copper-free aqueous Sonogashira coupling of aryl bromides generates the respective tolane derivatives in > 95 % yield.
Imidazol derivatives
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, (2008/06/13)
This invention relates to novel imidazole derivatives of formula a STR1 and pharmaceutically acceptable salts of these compounds, wherein R1, R2, R3, R5, R7 and R8 are as disclosed herein.
