18052-85-2Relevant academic research and scientific papers
Naphthalenes, isoquinolines, and a benzazocine from zirconocene - Copper-mediated coupling of benzocyclobutadiene with nitriles and alkynes
Ramakrishna,Sharp, Paul R.
, p. 877 - 879 (2003)
(Matrix presented) Commercially available 1-bromobenzocyclobutene is a potentially useful synthon particularly with the application of organometallic methodology. Here we show that it is readily converted into Cp 2Zr(benzocyclobutadiene), which couples with alkynes or nitriles giving five-membered zirconacycles. Treatment of these alkyne- or nitrile-derived zirconacycles with CuCl yields substituted naphthalenes, isoquinolines, or in the presence of MeO2C-CC-CO2Me, a 2-benzazocine containing an eight-membered ring.
Sodium silylsilanolate enables nickel-catalysed silylation of aryl chlorides
Hitoshio, Kenshiro,Yamagishi, Hiroki,Shimokawa, Jun,Yorimitsu, Hideki
supporting information, p. 6867 - 6870 (2021/07/19)
Structurally diverse aryl chlorides were silylated with sodium silylsilanolate reagents in the presence of a Ni(cod)2catalyst complexed with a phosphine ligand; PMe2Ph for electron-rich substrates, and PCy2Ph for electron-deficient ones. The mild reaction conditions allowed the silylation of various aryl chlorides including functionalised drug molecules.
Nickel-Catalyzed Decarbonylation of Acylsilanes
Ito, Yuri,Kodama, Takuya,Nakatani, Syun,Sakurai, Shun,Tobisu, Mamoru
, p. 7588 - 7594 (2020/06/27)
Nickel-catalyzed decarbonylation of acylsilanes is developed. In sharp contrast to cross-coupling reactions of acylsilanes, in which the silyl group serves as a leaving group, the silyl group is retained in the product in this decarbonylation reaction. Although the strong binding of the dissociated CO to the nickel center frequently hinders catalyst turnover in nickel-mediated decarbonylative reactions, this reaction can be catalyzed by nickel complexes bearing a CO ligand.
Oxidative 1,2-Difunctionalization of Ethylene via Gold-Catalyzed Oxyarylation
Harper, Matthew J.,Emmett, Edward J.,Bower, John F.,Russell, Christopher A.
supporting information, p. 12386 - 12389 (2017/09/22)
Under the conditions of oxidative gold catalysis, exposure of ethylene to aryl silanes and alcohols generates products of 1,2-oxyarylation. This provides a rare example of a process that allows catalytic differential 1,2-difunctionalization of this feedstock chemical.
Rhodium-Catalyzed Reductive Cleavage of Aryl Carbamates Using Isopropanol as a Reductant
Yasui, Kosuke,Higashino, Masaya,Chatani, Naoto,Tobisu, Mamoru
supporting information, p. 2569 - 2572 (2017/10/06)
Despite the widespread use of carbamates as a directing group in C-H bond-functionalization reactions, reductive removal of this directing group is not straightforward. Currently available methods are limited to nickel-catalyzed reactions using i PrMgX or hydrosilane as a reductant, leaving the functional group compatibility issue to be solved. Herein, we report rhodium-catalyzed reductive cleavage of aryl carbamates using i PrOH as a milder reductant.
Silyloxyarenes as Versatile Coupling Substrates Enabled by Nickel-Catalyzed C-O Bond Cleavage
Wiensch, Eric M.,Todd, David P.,Montgomery, John
, p. 5568 - 5571 (2017/09/15)
Silyloxyarenes are demonstrated to be a versatile substrate class in a variety of nickel-catalyzed coupling processes. The C(sp2)-O bond of aryl silyl ethers is directly transformed into C-H or C-Si bonds using Ti(O-i-Pr)4 or trialkylsilanes as reagents using nickel catalysts with N-heterocyclic carbene (NHC) ligands. Paired with the useful characteristics of silyl protecting groups, these methods enable protected hydroxyls to directly participate in high-value bond-forming steps rather than requiring deprotection-activation strategies that conventional approaches require. These processes of silyloxyarenes provide reactivity complementary to widely used phenol derivatives such as aryl pivalates, carbamates, and methyl ethers, thus enabling a powerful strategy for sequential chemoselective derivatization of complex substrates without protecting group and activating group manipulations.
Nickel-catalyzed reductive cleavage of aryl alkyl ethers to arenes in absence of external reductant
Tobisu, Mamoru,Morioka, Toshifumi,Ohtsuki, Akimichi,Chatani, Naoto
, p. 3410 - 3414 (2015/05/27)
The reductive cleavage of the C-O bonds of aryl ethers has great potential in organic synthesis. Although several catalysts that can promote the reductive cleavage of aryl ethers have been reported, all such systems require the use of an external reductant, e.g., hydrosilane or hydrogen. Here, we report the development of a new nickel-based catalytic system that can cleave the C-O bonds of ethers in the absence of an external reductant. The hydrogen atom required in this new reductive cleavage reaction is provided by the alkoxy group of the substrate, which serves as an internal reductant. The absence of an external reductant enables the unique chemoselectivity, i.e., the selective reduction of an alkoxy group over alkenes and ketones. This journal is
Gold-catalysed oxyarylation of styrenes and mono- and gem-disubstituted olefins facilitated by an iodine(III) oxidant
Ball, Liam T.,Lloyd-Jones, Guy C.,Russell, Christopher A.
supporting information; experimental part, p. 2931 - 2937 (2012/04/23)
1-Hydroxy-1,2-benziodoxol-3(1H)-one (IBA) is an efficient terminal oxidant for gold-catalysed, three-component oxyarylation reactions. The use of this iodine(III) reagent expands the scope of oxyarylation to include styrenes and gem-disubstituted olefins, substrates that are incompatible with the previously reported Selectfluor-based methodology. Diverse arylsilane coupling partners can be employed, and in benzotrifluoride, homocoupling is substantially reduced. In addition, the IBA-derived co-products can be recovered and recycled. The I's have it: The unprecedented use of an iodine(III) reagent as the terminal oxidant for gold-catalysed oxyarylation allows the substrate scope to be significantly expanded; in addition to monosubstituted olefins, styrenes and gem-disubstituted olefins are well tolerated (see scheme). With benzotrifluoride as solvent, unproductive homodimerisation of the arylsilane coupling partner is effectively suppressed. Copyright
Ni-catalyzed reduction of inert C-O bonds: A new strategy for using aryl ethers as easily removable directing groups
Alvarez-Bercedo, Paula,Martin, Ruben
supporting information; experimental part, p. 17352 - 17353 (2011/02/23)
An efficient Ni-catalyzed protocol for the reductive cleavage of inert C-O bonds has been developed. The method is characterized by its simplicity and wide scope, thereby allowing the use of aryl ethers as easily removable directing groups in organic synthesis.
Rhodium-catalyzed alkenylation of nitriles via silicon-assisted C-CN bond cleavage
Kita, Yusuke,Tobisu, Mamoru,Chatani, Naoto
supporting information; experimental part, p. 1864 - 1867 (2010/10/02)
Rhodium-catalyzed Mizoroki-Heck type reaction of nitriles via the cleavage of C-C bonds is described. Orthogonal and iterative functionalizations of arenes were also demonstrated by combining the present and conventional halide-based cross-coupling reacti
