146631-00-7Relevant articles and documents
Modulated SmAb phases formed by anchor shaped liquid crystalline molecules
Geese, Karina,Prehm, Marko,Tschierske, Carsten
, p. 9903 - 9906 (2014)
Bent-core molecules with a linear alkyl chain in the bay position (anchor shaped molecules) form new liquid crystalline phases combining periodicities with different coherence lengths in distinct directions; in these LC phases the molecules are organized on average orthogonal in modulated layers (ribbons or patches) with restricted rotation around the long axis, thus representing modulated SmAb phases.
Versatile synthesis of 4-aryl chroman and 1-aryl tetralins through metal-free reductive arylations
Panda, Gautam,Srinivas Lavanya Kumar
, p. 753 - 758 (2019)
A metal free approach was developed for accessing 4-aryl chromans and 1-aryl tetralins from their commercially available building blocks. This operationally simple protocol was well tolerated with the presence of labile functional groups, providing biologically relevant chemical libraries, which can be used for late stage modification. Dearylated analogues of the drugs Ormeloxifene and Lasofoxifene were synthesized using this approach.
The synthesis and thermal properties of novel heterocyclic liquid crystalline materials
Sharma, Sanjay,Lacey, David,Wilson, Paul
, p. 111/[225]-121/[235] (2003)
The synthesis and transition temperatures of a series of novel 2-(4-benzyloxyphenyl)-5-(5-alkylthiophen-2-yl)pyrimidine liquid crystals is described. Using a palladium-catalysed cross-coupling reaction benzyloxyphenylboronic acid was coupled to 5-bromo-2-
Preparation method of trans-ketone intermediate
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Paragraph 0068-0072; 0074, (2021/06/06)
The invention discloses a preparation method of trans-ketone intermediates. The trans-ketone intermediates comprise compounds as shown in a formula (I) and a formula (II). The preparation process comprises the following steps: (1) performing catalytic hydrogenation on the compounds as shown in the formula (I) to prepare ketone intermediate products; (2) preparing a Grignard reagent from benzyloxy halogenated benzene and magnesium powder, and performing acidolysis dehydration on the Grignard reagent and the ketone intermediate product prepared in the step (1) to obtain a compound as shown in a formula (II); and (3) carrying out catalytic hydrogenation and isomerization reaction on the compound as shown in the formula (II) prepared in the step (2). According to the preparation method provided by the invention, the technical problem that multiple benzyl alcohol impurities and impurity products after ketone condensation exist in acidolysis dehydration products of dicyclohexanone ethylene monoketal adopted in a traditional process is solved, and the purification difficulty of trans-ketone intermediate products is greatly reduced.
Pd- And Ni-Based Systems for the Catalytic Borylation of Aryl (Pseudo)halides with B2(OH)4
Munteanu, Charissa,Spiller, Taylor E.,Qiu, Jun,Delmonte, Albert J.,Wisniewski, Steven R.,Simmons, Eric M.,Frantz, Doug E.
, p. 10334 - 10349 (2020/09/18)
Despite recent advancements in metal-catalyzed borylations of aryl (pseudo)halides, there is a continuing need to develop robust methods to access both early-stage and late-stage organoboron intermediates amendable for further functionalization. In particular, the development of general catalytic systems that operate under mild reaction conditions across a broad range of electrophilic partners remains elusive. Herein, we report the development and application of three catalytic systems (two Pd-based and one Ni-based) for the direct borylation of aryl (pseudo)halides using tetrahydroxydiboron (B2(OH)4). For the Pd-based catalyst systems, we have identified general reaction conditions that allow for the sequestration of halide ions through simple precipitation that results in catalyst loadings as low as 0.01 mol % (100 ppm) and reaction temperatures as low as room temperature. We also describe a complementary Ni-based catalyst system that employs simple unligated Ni(II) salts as an inexpensive alternative to the Pd-based systems for the borylation of aryl (pseudo)halides. Extrapolation of all three systems to a one-pot tandem borylation/Suzuki-Miyaura cross-coupling is also demonstrated on advanced intermediates and drug substances.
Preparation method of hydroxyphenylboronic acid
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, (2020/05/08)
The invention discloses a preparation method of hydroxyphenylboronic acid, which belongs to the technical field of boric acid synthesis in medical intermediates. The method comprises the following steps: starting from bromophenol, carrying out BOC, trimethylsilyl or benzyl protection, forming a Grignard reagent, reacting with borate, or carrying out one-pot reaction with borate and n-butyllithium,and hydrolyzing to obtain hydroxyphenylboronic acid. According to the invention, cheap and easily available protecting groups are adopted, so that the protecting groups are easy to remove during boronation reaction hydrolysis, industrial amplification is easy to realize, batch production is carried out on the scale of dozens of kilograms, and the process stability is good.
Transition-Metal-Free Borylation of Aryl Bromide Using a Simple Diboron Source
Han, Min Su,Lim, Taeho,Ryoo, Jeong Yup
, p. 10966 - 10972 (2020/09/23)
In this study, we developed a simple transition-metal-free borylation reaction of aryl bromides. Bis-boronic acid (BBA), was used, and the borylation reaction was performed using a simple procedure at a mild temperature. Under mild conditions, aryl bromides were converted to arylboronic acids directly without any deprotection steps and purified by conversion to trifluoroborate salts. The functional group tolerance was considerably high. The mechanism study suggested that this borylation reaction proceeds via a radical pathway.
Towards New Oligomesogenic Phosphonic Acids as Stabilizers of Nanoparticles Colloids in Nematic Liquid Crystals
Prodanov, Maksym F.,Diakov, Maksym Y.,Vlasenko, Ganna S.,Vashchenko, Valerii V.
, p. 1905 - 1910 (2015/08/06)
Several synthetic strategies for the construction of linear and branched oligomesogenic phosphonic acids are examined, which differ in the method of building the key bimesogen unit. An efficient synthetic approach to the most promising compounds employs regioselective Kumada cross-coupling between [11-(4′-pentylbiphenyl-4-yl)undecyl]magnesium bromide and 4-(11-bromoundecyl)-4′-iodobiphenyl as the key step. Preliminary studies on the ability of the new ligands to stabilize nanoparticles colloids in nematic liquid crystals are undertaken for the example of quantum dots.
Sequential one-pot access to molecular diversity through aniline aqueous borylation
Erb, William,Albini, Mathieu,Rouden, Jacques,Blanchet, Jrme
, p. 10568 - 10580 (2015/01/08)
On the basis of our recently reported aniline aqueous borylation, molecular diversity was achieved in a one-pot process by combining other reactions such as esterification, Suzuki-Miyaura coupling, hydrogenolysis, or Petasis borono-Mannich.
Synthesis, structure and conformation of terphenylene-derived oxacalixaromatics
Hu, Wen-Jing,Zhao, Xiao-Li,Ma, Ming-Liang,Guo, Fang,Mi, Xian-Qiang,Jiang, Biao,Wen, Ke
supporting information; experimental part, p. 1448 - 1454 (2012/04/11)
Oxacalix[4]aromatics comprised of terphenylene units have been synthesized by cyclooligomerization of 5′-tert-butyl-1,1′:3′,1″- terphenyl-4,4″-diol (1) and electron-deficient meta-dihalogenated benzene and heterocycles. Single-crystal X-ray analysis revealed that oxacalix[2]terphenylene[2]pyrazine 13 adopts a chair conformation, forming a molecular cavity to trap an ethyl acetate guest molecule in the solid state. 1,3-Alternate conformations are adopted by other oxacalix[2]terphenylene[2] aromatics (11, 12 and 15), which form a narrow tweezer-like molecular cavity that is incapable of encapsulating any guest molecules. Oxacalix[4]aromatics comprised of terphenylene units have been synthesized, andtheir structures and conformations have been elucidated. Copyright
