269410-07-3Relevant articles and documents
Singly and Doubly 1,2-Phenylene-Inserted Porphyrin Arch-Tape Dimers: Synthesis and Highly Contorted Structures
Fukui, Norihito,Osuka, Atsuhiro
, p. 6304 - 6308 (2018)
Singly and doubly 1,2-phenylene-inserted NiII porphyrin arch-tape dimers 3 and 9 were synthesized from the corresponding β-to-β 1,2-phenylene-bridged NiII porphyrin dimers 5 and 11 via Ni0-mediated reductive cyclization an
Ir-Catalyzed Ligand-Free Directed C-H Borylation of Arenes and Pharmaceuticals: Detailed Mechanistic Understanding
Mahamudul Hassan, Mirja Md,Mondal, Biplab,Singh, Sukriti,Haldar, Chabush,Chaturvedi, Jagriti,Bisht, Ranjana,Sunoj, Raghavan B.,Chattopadhyay, Buddhadeb
, p. 4360 - 4375 (2022/03/16)
An efficient method for Ir-catalyzed ligand free ortho borylation of arenes (such as, 2-phenoxypyridines, 2-anilinopyridines, benzylamines, benzylpiperazines, benzylmorpholines, benzylpyrrolidine, benzylpiperidines, benzylazepanes, α-amino acid derivatives, aminophenylethane derivatives, and other important scaffolds) and pharmaceuticals has been developed. The reaction underwent via an interesting mechanistic pathway, as revealed by the detailed mechanistic investigations by using kinetic isotope studies and DFT calculations. The catalytic cycle is found to involve the intermediacy of an Ir-boryl complex where the substrate C-H activation is the turnover determining step, intriguingly without any appreciable primary KIE. The method displays a broad range of substrate scope and functional group tolerance. Numerous late-stage borylation of various important molecules and drugs were achieved using this developed strategy. The borylated compounds were further converted into more valuable functionalities. Moreover, utilizing the benefit of the B-N intramolecular interaction of the mono borylated compounds, an operationally simple method has been developed for the selective diborylation of 2-phenoxypyridines and numerous functionalized arenes. Furthermore, the synthetic utility has been showcased with the removal of the pyridyl directing group from the borylated product to achieve ortho borylated phenol along with the ipso-borylation for the preparation of 1,2-diborylated benzene.
Visible-Light-Induced Ni-Catalyzed Radical Borylation of Chloroarenes
Tian, Ya-Ming,Guo, Xiao-Ning,Krummenacher, Ivo,Wu, Zhu,Nitsch, J?rn,Braunschweig, Holger,Radius, Udo,Marder, Todd B.
supporting information, p. 18231 - 18242 (2020/11/02)
A highly selective and general photoinduced C-Cl borylation protocol that employs [Ni(IMes)2] (IMes = 1,3-dimesitylimidazoline-2-ylidene) for the radical borylation of chloroarenes is reported. This photoinduced system operates with visible light (400 nm) and achieves borylation of a wide range of chloroarenes with B2pin2 at room temperature in excellent yields and with high selectivity, thereby demonstrating its broad utility and functional group tolerance. Mechanistic investigations suggest that the borylation reactions proceed via a radical process. EPR studies demonstrate that [Ni(IMes)2] undergoes very fast chlorine atom abstraction from aryl chlorides to give [NiI(IMes)2Cl] and aryl radicals. Control experiments indicate that light promotes the reaction of [NiI(IMes)2Cl] with aryl chlorides generating additional aryl radicals and [NiII(IMes)2Cl2]. The aryl radicals react with an anionic sp2-sp3 diborane [B2pin2(OMe)]- formed from B2pin2 and KOMe to yield the corresponding borylation product and the [Bpin(OMe)]?- radical anion, which reduces [NiII(IMes)2Cl2] under irradiation to regenerate [NiI(IMes)2Cl] and [Ni(IMes)2] for the next catalytic cycle.
Room temperature Pd(0)/Ad3P-catalyzed coupling reactions of aryl chlorides with bis(pinacolato)diboron
Dong, Jie,Guo, Hui,Peng, Wei,Hu, Qiao-Sheng
supporting information, p. 760 - 763 (2019/02/16)
Room temperature Pd(0)/Ad3P-catalyzed cross-coupling reactions of aryl chlorides with bis(pinacolato)diboron are described. The Pd(0)/Ad3P catalyst, generated from Ad3P-coordinated acetanilide-based palladacycle complex, proved to be an efficient catalyst system for the Miyaura borylation reactions of a variety of aryl chlorides with bis(pinacolato)diboron. The mild reaction condition, the easy availability of the catalyst and good coupling yields make these reactions potentially useful in organic synthesis.
Bedford-type palladacycle-catalyzed miyaura borylation of aryl halides with tetrahydroxydiboron in water
Zernickel, Anna,Du, Weiyuan,Ghorpade, Seema A.,Sawant, Dinesh N.,Makki, Arwa A.,Sekar, Nagaiyan,Eppinger, J?rg
, p. 1842 - 1851 (2018/02/23)
A mild aqueous protocol for palladium catalyzed Miyaura borylation of aryl iodides, aryl bromides and aryl chlorides with tetrahydroxydiboron (BBA) as a borylating agent is developed. The developed methodology requires low catalyst loading of Bedford-type palladacycle catalyst (0.05 mol %) and works best under mild reaction conditions at 40 °C in short time of 6 h in water. In addition, our studies show that for Miyaura borylation using BBA in aqueous condition, maintaining a neutral reaction pH is very important for reproducibility and higher yields of corresponding borylated products. Moreover, our protocol is applicable for a broad range of aryl halides, corresponding borylated products are obtained in excellent yields up to 93% with 29 examples demonstrating its broad utility and functional group tolerance.
Copper-Catalyzed ipso-Borylation of Fluoroarenes
Niwa, Takashi,Ochiai, Hidenori,Hosoya, Takamitsu
, p. 4535 - 4541 (2017/07/24)
ipso-Borylation of fluoroarenes has been achieved using an air-stable copper complex as a catalyst. Mechanistic studies suggest that the reaction proceeds via an SRN1 mechanism involving a single-electron-transfer (SET) process and not via the typical SNAr mechanism. This method differs from the previously reported nickel/copper-cocatalyzed system in terms of scope of the substrate and has exhibited good scalability. Double and triple ipso-borylations of several di- and trifluoroarenes have been also achieved efficiently, enhancing the synthetic utility of this method.
Regioselective Synthesis of o-Benzenediboronic Acids via Ir-Catalyzed o-C-H Borylation Directed by a Pyrazolylaniline-Modified Boronyl Group
Yamamoto, Takeshi,Ishibashi, Aoi,Suginome, Michinori
supporting information, p. 886 - 889 (2017/02/26)
Ir-catalyzed ortho-directed C-H borylation of pyrazolylaniline (PZA)-modified arylboronic acids with bis(pinacolate)diboron afforded o-benzenediboronic acids in which two boronyl groups are differentially modified by pinacol (PIN) and PZA. By using this borylation after nondirected Ir-catalyzed C-H borylation, o-benzenediboronic acids are conveniently synthesized from unfunctionalized arenes. The differentially modified o-benzenediboronic acids undergo selective oxidation and Suzuki-Miyaura cross-coupling at the PZA-modified boronyl groups, affording o-functionalized arylboronic acids selectively.
Lewis Acid–Base Interaction-Controlled ortho-Selective C?H Borylation of Aryl Sulfides
Li, Hong Liang,Kuninobu, Yoichiro,Kanai, Motomu
supporting information, p. 1495 - 1499 (2017/02/05)
An iridium/bipyridine-catalyzed ortho-selective C?H borylation of aryl sulfides was developed. High ortho-selectivity was achieved by a Lewis acid–base interaction between a boryl group of the ligand and a sulfur atom of the substrate. This is the first example of a catalytic and regioselective C?H transformation controlled by a Lewis acid–base interaction between a ligand and a substrate. The C?H borylation reaction could be conducted on a gram scale, and with a bioactive molecule as a substrate, demonstrating its applicability to late-stage regioselective C?H borylation. A bioactive molecule was synthesized from an ortho-borylated product by converting the boryl and methylthio groups of the product.
Additive- and Metal-Free, Predictably 1,2- and 1,3-Regioselective, Photoinduced Dual C-H/C-X Borylation of Haloarenes
Mfuh, Adelphe M.,Nguyen, Vu T.,Chhetri, Bhuwan,Burch, Jessica E.,Doyle, John D.,Nesterov, Vladimir N.,Arman, Hadi D.,Larionov, Oleg V.
supporting information, p. 8408 - 8411 (2016/07/27)
We report herein a simple, additive- and metal-free, photoinduced, dual C-H/C-X borylation of chloro-, bromo-, and iodoarenes. The reaction produces 1,2- and 1,3-diborylarenes on gram scales under batch and continuous flow conditions. The regioselectivity of the dual C-H/C-X borylation is determined by the solvent and the substituents in the parent haloarenes.
Zinc-Catalyzed Dual C-X and C-H Borylation of Aryl Halides
Bose, Shubhankar Kumar,Deissenberger, Andrea,Eichhorn, Antonius,Steel, Patrick G.,Lin, Zhenyang,Marder, Todd B.
supporting information, p. 11843 - 11847 (2015/10/05)
A zinc-catalyzed combined C-X and C-H borylation of aryl halides using B2pin2 (pin=OCMe2CMe2O) to produce the corresponding 1,2-diborylarenes under mild conditions was developed. Catalytic C-H bond activation occurs ortho to the halide groups if such a site is available or meta to the halide if the ortho position is already substituted. This method thus represents a novel use of a groupXII catalyst for C-H borylation. This transformation does not proceed via a free aryne intermediate, but a radical process seems to be involved. Two B or not two B: A novel catalytic system based on a ZnII-dtbpy precursor was developed for the preparation of 1,2-diborylarenes. This method represents a new type of catalytic process for diborylation of aryl halides via both C-X and C-H activation.
