5720-07-0Relevant articles and documents
Functionalised 2,2′-bipyridine ligands for the preparation of metallostars; X-ray structures of free ligands and preparation of copper(I) and silver(I) complexes
Constable, Edwin C.,Housecroft, Catherine E.,Neuburger, Markus,Poleschak, Ingo,Zehnder, Margareta
, p. 93 - 108 (2003)
2,2-Bipyridine ligands bearing functionalised aryl substituents have been prepared with the aim of subsequent functionalisation and the preparation of multinuclear metallostars. The key intermediates are compounds containing 4-methoxyphenyl substituents w
An Accelerated Modular-Orthogonal Ni-Catalyzed Methodology to Symmetric and Nonsymmetric Constitutional Isomeric AB2to AB9Dendrons Exhibiting Unprecedented Self-Organizing Principles
Daud, Hina,Hoffman, David J.,Huang, Ning,Jezorek, Ryan L.,Malineni, Jagadeesh,McClure, Emily R.,Partridge, Benjamin E.,Percec, Virgil,Peterca, Mihai,Sahoo, Dipankar,Song, Se Lin,Sung, Paul D.,Wang, Shitao,Wang, Xuefeng,Zhang, Na
supporting information, p. 17724 - 17743 (2021/11/04)
Five libraries of natural and synthetic phenolic acids containing five AB3, ten constitutional isomeric AB2, one AB4, and one AB5 were previously synthesized and reported by our laboratory in 5 to 11 steps. They were employed to construct seven libraries of self-assembling dendrons, by divergent generational, deconstruction, and combined approaches, enabling the discovery of a diversity of supramolecular assemblies including Frank-Kasper phases, soft quasicrystals, and complex helical organizations, some undergoing deracemization in the crystal state. However, higher substitution patterns within a single dendron were not accessible. Here we report three libraries consisting of 30 symmetric and nonsymmetric constitutional isomeric phenolic acids with unprecedented sequenced patterns, including two AB2, three AB3, eight AB4, five AB5, six AB6, three AB7, two AB8, and one AB9 synthesized by accelerated modular-orthogonal Ni-catalyzed borylation and cross-coupling. A single etherification step with 4-(n-dodecyloxy)benzyl chloride transformed all these phenolic acids, of interest also for other applications, into self-assembling dendrons. Despite this synthetic simplicity, they led to a diversity of unprecedented self-organizing principles: lamellar structures of interest for biological membrane mimics, helical columnar assemblies from rigid-solid angle dendrons forming Tobacco Mosaic Virus-like assemblies, columnar organizations from adaptable-solid angle dendrons forming disordered micellar-like nonhelical columns, columns from supramolecular spheres, five body-centered cubic phases displaying supramolecular orientational memory, rarely encountered in previous libraries forming predominantly Frank-Kasper phases, and two Frank-Kasper phases. Lessons from these self-organizing principles, discovered within a single generation of self-assembling dendrons, may help elaborate design principles for complex helical and nonhelical organizations of synthetic and biological matter.
Asymmetric 1,4-Addition of Arylboronic Acids to β,γ-Unsaturated α-Ketoesters using Heterogeneous Chiral Metal Nanoparticle Systems
Miyamura, Hiroyuki,Yasukawa, Tomohiro,Zhu, Zhiyuan,Kobayashi, Shū
supporting information, p. 353 - 359 (2019/12/15)
Asymmetric 1,4-addition reactions with β,γ-unsaturated α-ketoesters are valuable because the resulting chiral ketoester compounds can be converted into various useful species that are often used as chiral building blocks in drug and natural product synthesis. However, β,γ-unsaturated α-ketoesters have two reactive points in terms of nucleophilic additions, which will lead to the 1,4-adduct, the 1,2-adduct and to the combined 1,4- and 1,2-adduct. Therefore, controlling this chemoselectivity is an important factor for the development of these transformations. Here, we developed an asymmetric 1,4-addition of aryl boronic acids to β,γ-unsaturated α-ketoesters by using heterogeneous chiral rhodium nanoparticle systems with a chiral diene ligand bearing a secondary amide moiety. The newly developed polydimethylsilane-immobilized rhodium nanoparticle catalysts showed high activity, high chemoselectivity, and excellent enantioselectivity, and this is the first heterogeneous catalytic system for this asymmetric reaction. Metal nanoparticle catalysts were recovered and reused without loss of activity or leaching of metal. (Figure presented.).
Aryl boronic acid preparation method
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Paragraph 0033-0039, (2020/01/25)
The invention belongs to the technical field of fine chemical engineering, and relates to an aryl boronic acid preparation method. In the prior art, aryl boronic acid as a novel safe and environmentally-friendly arylation reagent is widely used in scientific research and production of various fine chemicals containing aryl structures in the fields of medicines, pesticides, advanced materials and the like; and the aryl boronic acid compound preparation method reported in the disclosed literature has problems of harsh reaction conditions and high cost. A purpose of the invention is to provide amethod, wherein an aryl boron compound is formed by carrying out a reaction on a Grignard reagent and trialkyl borate under mild conditions, the composition of the aryl boron compound is converted from the main component diaryl borate into the main component aryl borate, and the aryl borate is hydrolyzed to obtain aryl boric acid, so that the preparation cost of the acyl aryl boric acid compound can be remarkably reduced, and the method has good practical application prospect.
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.
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.
Palladium-catalyzed B-diarylation of diethylaminoborane for the synthesis of diarylborinic acids
Igarashi, Takuya,Shimazumi, Ryoma,Tobisu, Mamoru
supporting information, p. 760 - 763 (2020/07/10)
The palladium-catalyzed synthesis of diarylborinic acid derivatives by intermolecular cross-coupling between aryl iodides and (amino)dihydrideborane is reported. The key to success of the reaction is the use of a less bulky diethylaminoborane reagent, which facilitates the second B-arylation.
Conformational restriction design of thiophene-biphenyl-DAPY HIV-1 non-nucleoside reverse transcriptase inhibitors
Sang, Yali,Han,Pannecouque, Christophe,De Clercq, Erik,Zhuang, Chunlin,Chen
, (2019/08/20)
Conformational restriction is a promising strategy in the development of DAPY-type non-nucleoside reverse transcriptase inhibitors (NNRTIs). Herein, eighteen thiophene-biphenyl-DAPY derivatives were designed and synthesized as potent HIV-1 NNRTIs in which halogen and methyl groups were introduced to explore the conformationally constrained effects. Molecular docking and dynamic simulation analysis indicated that substituents on different positions of the biphenyl ring induced different dihedral angles and binding conformations, further explaining their anti-viral activities. The 2′-fluoro and 3′-chloro substitutions could form electrostatic or halogen-bonding interactions with adjacent residues of the RT enzyme. The 2′-methyl group contributed to enlarge the dihedral angle of biphenyl ring and was positioned to a space-filling hydrophobic pocket. Notably, compounds 22 and 23 with two methyl groups exhibited potent biological activity against WT HIV-1-infected MT-4 cells (EC50 = 14 and 17 nM, respectively) and RT enzyme (EC50 = 27 and 42 nM, respectively). In particular, 23 exhibited much lower cytotoxicity (CC50 = 264.19 μM) and higher selectivity index (SI = 18,564) than etravirine. Taken together, a rational conformational model for further design of DAPYs is proposed, providing a new guidance for the development of NNRTIs.
Magnesium promoted autocatalytic dehydrogenation of amine borane complexes: A reliable, non-cryogenic, scalable access to boronic acids
Marciasini, Ludovic D.,Richard, Jimmy,Cacciuttolo, Bastien,Sartori, Guillaume,Birepinte, Melodie,Chabaud, Laurent,Pinet, Sandra,Pucheault, Mathieu
, p. 164 - 171 (2018/12/05)
Owing to the unusual reactivity of dialkylamine-borane complexes, a methodology was developed to simply access boronic acids. The intrinsic instability of magnesium aminoborohydride was tweaked into a tandem dehydrogenation borylation sequence. Proceeding via an autocatalytic cycle, amineborane dehydrogenation was induced by a variety of Grignard reagents. Overall, addition of the organomagnesium species onto specially designed dialkylamine-borane complexes led to a variety of boronic acids in high yields. In addition, the reaction can be performed under Barbier conditions, on a large scale.
Additive- and Photocatalyst-Free Borylation of Arylazo Sulfones under Visible Light
Xu, Yuliang,Yang, Xinying,Fang, Hao
, p. 12831 - 12837 (2018/10/20)
We developed a photocatalyst-free and additive-free, visible light induced borylation reaction using arylazo sulfones as starting material. This protocol shows some advantages such as mild conditions, simple equipment, and wide substrate scope, which gives a complementary protocol for the preparation of arylboronates.
