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.
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 hydroxyphenylboronic acid
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Paragraph 0022-0023; 0025, (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.
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.
