- Modulated SmAb phases formed by anchor shaped liquid crystalline molecules
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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.
- Geese, Karina,Prehm, Marko,Tschierske, Carsten
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Read Online
- Versatile synthesis of 4-aryl chroman and 1-aryl tetralins through metal-free reductive arylations
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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.
- Panda, Gautam,Srinivas Lavanya Kumar
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Read Online
- The synthesis and thermal properties of novel heterocyclic liquid crystalline materials
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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-
- Sharma, Sanjay,Lacey, David,Wilson, Paul
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p. 111/[225]-121/[235]
(2003)
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Read Online
- Preparation method of trans-ketone intermediate
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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.
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Paragraph 0068-0072; 0074
(2021/06/06)
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- Preparation method of hydroxyphenylboronic acid
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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.
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Paragraph 0022-0023; 0025
(2020/05/08)
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- Transition-Metal-Free Borylation of Aryl Bromide Using a Simple Diboron Source
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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.
- Han, Min Su,Lim, Taeho,Ryoo, Jeong Yup
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p. 10966 - 10972
(2020/09/23)
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- Pd- And Ni-Based Systems for the Catalytic Borylation of Aryl (Pseudo)halides with B2(OH)4
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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.
- Munteanu, Charissa,Spiller, Taylor E.,Qiu, Jun,Delmonte, Albert J.,Wisniewski, Steven R.,Simmons, Eric M.,Frantz, Doug E.
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p. 10334 - 10349
(2020/09/18)
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- Towards New Oligomesogenic Phosphonic Acids as Stabilizers of Nanoparticles Colloids in Nematic Liquid Crystals
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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.
- Prodanov, Maksym F.,Diakov, Maksym Y.,Vlasenko, Ganna S.,Vashchenko, Valerii V.
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p. 1905 - 1910
(2015/08/06)
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- Sequential one-pot access to molecular diversity through aniline aqueous borylation
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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.
- Erb, William,Albini, Mathieu,Rouden, Jacques,Blanchet, Jrme
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p. 10568 - 10580
(2015/01/08)
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- Synthesis, structure and conformation of terphenylene-derived oxacalixaromatics
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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
- Hu, Wen-Jing,Zhao, Xiao-Li,Ma, Ming-Liang,Guo, Fang,Mi, Xian-Qiang,Jiang, Biao,Wen, Ke
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p. 1448 - 1454
(2012/04/11)
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- New SmCG phases in a hydrogen-bonded bent-core liquid crystal featuring a branched siloxane terminal group
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In this study, we synthesized three analogous bent-core molecules, a hydrogen-bonded complex and a covalent-bonded compound with branched siloxane units (H-SiO and C-SiO, respectively) and a hydrogen-bonded complex with an alkyl unit (H-Alk), and investigated the effects of the hydrogen bonding and branched siloxane terminal units on their mesomorphic properties. The covalent-bonded compound C-SiO and the hydrogen-bonded complex H-Alk exhibited typical SmCP phases; in contrast, the hydrogen-bonded complex H-SiO exhibited a series of general tilt smectic (SmCG) phases with highly ordered layer structures (i.e., SmCG2PF-USmCG2P A-SmCG2PF-SmCGPF upon cooling). During the SmCG-type phase transition process, a 2D-modulated ribbon structure transferred into highly ordered layers via undulated layers, as the hydrogen-bonding strength increased with reduced temperatures. As the SmCG domains were aligned under dc electric fields, a gradual decrease in the leaning angle from ca. 60° to 50° (while the tilt angle kept at ca. 31°) could be determined by in situ wide-angle X-ray scattering (WAXS). Combined with Fourier transform infrared and Raman spectroscopic data, our results suggest that the change in the leaning angle was governed by the competition of the hydrogen bonds and microsegregation of siloxane units within the bilayer structure of the hydrogen-bonded complex H-SiO. In addition, the ferroelectric-(antiferroelectric)-ferroelectric transitions proven by the switching current responses in the SmCG-type phases of H-SiO reveal that the polar switching occurred through collective rotations around the long axis of H-SiO. Therefore, novel SmCG phases with a series of highly ordered 2D-structures were induced by the effects of the hydrogen bonding and branched terminal siloxane unit in the bent-core hydrogen-bonded LC complex H-SiO.
- Chen, Wei-Hong,Chuang, Wei-Tsung,Jeng, U-Ser,Sheu, Hwo-Shuenn,Lin, Hong-Cheu
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p. 15674 - 15685
(2011/11/28)
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- Smectic-layer alignments of surface-modified gold nanoparticles in the nanocomposite induced by a hydrogen-bonded bent-core liquid crystalline host under electric fields
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Packing tips: The layer spacing of 5.5 nm (see TEM image) of the nanocomposite VPy-SiA/AuNPs-S (5 wt %) under DC/AC electric fields perfectly matches the d spacing of 5.5 nm obtained by in situ XRD measurements under a DC electric field. TEM images revealed that the well-organized packing of layers of surface-modified gold NPs could be induced in the nanocomposite under electric fields. Copyright
- Chen, Wei-Hong,Chang, Yi-Ting,Lee, Jey-Jau,Chuang, Wei-Tsung,Lin, Hong-Cheu
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p. 13182 - 13187
(2012/02/02)
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- Asymmetric synthesis of a tricyclic benzofuran motif: A privileged core structure in biologically active molecules
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An efficient synthetic strategy for the asymmetric synthesis of a hexahydrodibenzofuran core structure, with a quaternary stereogenic center, emerges by employing a chiral reduction using Corey's (S)-Me-CBS-oxazaborolidine reagent followed by a Mitsunobu reaction to set the stereochemistry. A Pd-mediated intramolecular Heck reaction concludes the tricyclic core structure. Finally, a Pd/C catalyzed reduction yields the target molecule in 21% overall yield over 6 steps.
- Sunden, Henrik,Olsson, Roger
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supporting information; experimental part
p. 4831 - 4833
(2010/12/20)
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- Snowflake-Like Dendrimers via Site-Selective Synthesis of Dendrons
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(Equation presented) Snowflake-shaped dendrimers were prepared via site-selective synthesis of dendrons, where an attachment of encapsulating dendritic branches and an extension of phenylacetylenic units were alternatively manipulated on the structure of
- Kozaki, Masatoshi,Okada, Keiji
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p. 485 - 488
(2007/10/03)
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- Hydrogen-bonded banana liquid crystals
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Top banana! Hydrogen-bonded bent complexes of benzoic acids (H donor) and nonmesomorphic V-shaped 4′-stilbazoles (H acceptor) give rise to polar smectic C (SmCP, see graphic) mesophases. The multifunctional character of these noncovalent materials is conf
- Gimeno, Nelida,Ros, Maria Blanca,Serrano, Jose Luis,De La Fuente, Maria Rosario
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p. 5235 - 5238
(2007/10/03)
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- Biphenyl compounds and their use as oestrogenic agents
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Compounds of formula (I), wherein [X] represents aromatic carbocyclic rings (A) and (B), where R1, R2, R3, R4, R5, R6and R7are as defined in the description, salts thereof, a method and intermediates for preparing same, the use thereof as drugs, and pharmaceutical compositions containing same, are disclosed.
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Page column 7-8
(2010/11/29)
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- Total synthesis of pyridovericin: studies toward the biomimetic synthesis of pyridomacrolidin.
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[reaction: see text] The total synthesis of the novel metabolite pyridovericin 1 is reported. The synthesis of this key intermediate in our proposed biomimetic synthesis of pyridomacrolidin 2 has been accomplished in good yield from readily available 2,4-dihydroxypyridine.
- Baldwin, Jack E,Adlington, Robert M,Conte, Aurelia,Irlapati, Nageswara Rao,Marquez, Rodolfo,Pritchard, Gareth J
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p. 2125 - 2127
(2007/10/03)
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- Polymerizable compound, polymerizable resin composition, cured polymer and liquid crystal display device
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The polymerizable compound of this invention is represented by general formula (I): where R is H, R′, R′O, R′COO, or R′OCO, R′ is a linear or branched alkyl group or alkenyl group having 1 to about 15 carbon atoms, A1 and A2 are independently a cyclohexane ring or a benzene ring which may include a substituent represented by formula (II) below; X is H or CH3; and Y1, Y2, Y3, and Y4 are independently H, F, Cl, CH3, CH3O, CF3, or CF3O wherein at least two of Y1, Y2, Y3, and Y4 are H and, if both A1 and A2 are cyclohexane rings, at least one of Y1, Y2, Y3, and Y4 is not H: where Y5, Y6, Y7, and Y8 are independently H, F, Cl, CH3, CH3O, CF3, or CF3O, at least two of Y5, Y6, Y7, and Y8 are H.
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Page column 35
(2010/02/05)
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- Biphenyl compounds and use thereof as oestrogenic agents
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A compound having the formula wherein R5 is an [A]—CH3, —[A]—C(OH)ZZ′ or —[A]—C(O)Z″ grouping where —[A]— is an alkylene, alkenylene or alkynylene radical or a single bond, and Z, Z′ and Z″ are a hydrogen atom or an optionally substituted alkyl, alkenyl, alkynyl or aryl radical; and R1, R2, R3, R4, R6, R7 and R8 are as defined in the description; the use thereof as a drug, pharmaceutical compositions containing same, a preparation method therefor, and intermediates of said method, are disclosed.
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- Biphenyl compounds and use thereof as oestrogenic agents
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PCT No. PCT/FR97/00184 Sec. 371 Date Aug. 28, 1998 Sec. 102(e) Date Sep. 28, 1998 PCT Filed Jan. 30, 1997 PCT Pub. No. WO97/28116 PCT Pub. Date Aug. 7, 1997Compounds of formula (I), wherein [X] represents aromatic carbocyclic rings (A) and (B), where R1, R2, R3, R4, R5, R6 and R7 are as defined in the description, salts thereof, a method and intermediates for preparing same, the use thereof as drugs, and pharmaceutical compositions containing same, are disclosed.
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- The use of a modified Suzuki reaction for the synthesis of monoarylferrocenes
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A modification of the Suzuki cross-coupling reaction proved to be a clean and useful method for the preparation of monosubstituted arylferrocenes. Iodoferrocene was reacted with a series of substituted arylboronic acids in the presence of sodium carbonate and palladium acetate in aqueous ethanol at room temperature to produce a range of substituted monoarylferrocenes. A systematic investigation undertaken to determine optimal reaction conditions indicated that scrupulous deoxygenation of the solvent is critical. The use of stronger bases such as barium hydroxide and potassium carbonate is favourable and gives rise to better yields of monoarylferrocenes. The reactions also proceed efficiently in aqueous DMF, broadening the scope of the reaction allowing efficient reactions with boronic acids that show low solubility in organic solvents.
- Imrie, Christopher,Loubser, Christa,Engelbrecht, Pieter,McCleland, Cedric W.
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p. 2513 - 2523
(2007/10/03)
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- Synthesis of C-ring hydroxylated neoflavonoids by ligand coupling reactions
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Reaction of 4-trifluoromethanesulfonyloxycoumarin derivatives with benzyloxyphenylboronic acid derivatives under modified Suzuki reaction conditions afforded the corresponding neoflavones. Selective debenzylation took place in high yields when the palladi
- Donnelly, Dervilla M.X.,Finet, Jean-Pierre,Guiry, Patrick J.,Rea, Martin D.
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p. 2719 - 2730
(2007/10/03)
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- Biphenyl compounds
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Novel compounds of the formula STR1 wherein the substituents are defined as in the application and their salts with non-toxic, pharmaceutically acceptable acids and bases having 5-α-reductase inhibiting activity and a process and intermediates for their preparation.
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- PHENYL SULFONAMIDE ENDOTHELIN ANTAGONISTS
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Compounds of the formula STR1 inhibit the activity of endothelin. The symbols are defined as follows: R 1, R 2 and R. sup.3 are each independently(a) hydrogen, except that R. sup.1 is other than hydrogen;(b) alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl, cycloalkylalkyl, cycloalkenyl, cycloalkenylalkyl, aryl, aryloxy, aralkyl or aralkoxy, any of which may be substituted with Z 1, Z 2 and Z. sup.3 ;(c) halo;(d) hydroxyl;(e) cyano; (f) nitro; (g)--C(O)H or--C(O)R 6 ;(h)--CO 2 H or--CO 2 R 6 ; (i)--SH,--S(O) n R 6,--S(O) m--OH,--S(O) m--OR 6,--O--S(O) m--R 6,--O--S(O) m OH or--O--S(O) m--OR. sup.6 ;(j)--Z. sup.4--NR 7 R 8 ; or (k)--Z 4--N(R 11--Z 5--NR 9 R 10 ; and the remaining symbols are as defined in the specification.
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