109306-86-7Relevant articles and documents
Aryl-Fluoride Bond-Forming Reductive Elimination from Nickel(IV) Centers
Meucci, Elizabeth A.,Ariafard, Alireza,Canty, Allan J.,Kampf, Jeff W.,Sanford, Melanie S.
, p. 13261 - 13267 (2019)
The treatment of pyridine- and pyrazole-ligated NiII σ-aryl complexes with Selectfluor results in C(sp2)-F bond formation under mild conditions. With appropriate design of supporting ligands, diamagnetic NiIV σ-aryl fluoride intermediates can be detected spectroscopically and/or isolated during these transformations. These studies demonstrate for the first time that NiIV σ-aryl fluoride complexes participate in challenging C(sp2)-F bond-forming reductive elimination to yield aryl fluoride products.
Co(III)-catalyzed C-H activation/formal SN-type reactions: Selective and efficient cyanation, halogenation, and allylation
Yu, Da-Gang,Gensch, Tobias,De Azambuja, Francisco,Vsquez-Cspedes, Suhelen,Glorius, Frank
, p. 17722 - 17725 (2014)
The first cobalt-catalyzed cyanation, halogenation, and allylation via C-H activation have been realized. These formal SN-type reactions generate valuable (hetero)aryl/alkenyl nitriles, iodides, and bromides as well as allylated indoles using a bench-stable Co(III) catalyst. High regio- and mono-selectivity were achieved for these reactions. Additionally, allylation proceeded efficiently with a turnover number of 2200 at room temperature, which is unprecedented for this Co(III) catalyst. Alkenyl substrates and amides have been successfully utilized in CpCo(III)-catalyzed C-H activation for the first time.
Directed C?H Activation and Tandem Cross-Coupling Reactions Using Palladium Nanocatalysts with Controlled Oxidation
Kim, Kiseong,Jung, Younjae,Lee, Suyeon,Kim, Mijong,Shin, Dongwoo,Byun, Hyeeun,Cho, Sung June,Song, Hyunjoon,Kim, Hyunwoo
, p. 6952 - 6956 (2017)
Controlled oxidation of palladium nanoparticles provided high-valent PdIV oxo-clusters which efficiently promote directed C?H halogenation reactions. In addition, palladium nanoparticles can undergo changes in oxidation states to provide both high-valent PdIV and low-valent Pd0 species within one system, and thus a tandem reaction of C?H halogenation and cross-coupling (C?N, C?C, and C?S bond formation) was successfully established.
Isolation of Homoleptic Dicationic Tellurium and Monocationic Bismuth Analogues of Non-N-Heterocyclic Carbene Derivatives
Butcher, Ray J.,Deacon, Glen B.,Deka, Rajesh,Junk, Peter C.,Sarkar, Arup,Singh, Harkesh B.,Turner, David R.
, (2020)
The first examples of Te analogues of non-N-heterocyclic carbene (non-NHC) derivatives, [(ppy)2Te]·2ClO4, [4]·2ClO4, and[(ppy)2Te]·2OTf, [5]·2OTf [where ppy = 2-(2′-pyridyl)phenyl and Tf = O2SCF3] are reported by the metathesis reaction of diorganoiodotelluronium(IV) cation, [(ppy)2TeI]·I3, [3]·I3, with AgClO4 and AgOTf, respectively. The metathesis reaction of ppyTeCl3, 6, with an excess of AgClO4 resulted in the isolation of [ppyTe(μ-O)]2·2ClO4, [8]·2ClO4. The reaction of triorganotelluronium(IV) cation [(ppy)3Te]·Br, [10]Br, with K2PdCl4 afforded [(ppy)2TeCl]·[(ppy)PdCl2], 11. The generality of the "ppy" group on stabilizing other main-group non-NHC analogues has been further established by synthesizing the second example of a Bi analogue of a non-NHC derivative, namely, bismuthenium ion, [(ppy)2Bi]·Cl, [12]·Cl, using the same aryl group. All of the synthesized compounds are unambiguously authenticated by single-crystal X-ray diffraction studies. DFT calculations [natural bond orbital (NBO), atoms in molecules (AIM), and electron localization function (ELF)] indicate that the stability of the non-NHC carbenoids relies on the σ-hole participation of the Te/Bi atom with the strong intramolecular coordination ability of the pyridyl N atom of the aryl substituent.
Chelating N-heterocyclic carbene alkoxide as a supporting ligand for PdII/IV C-H bond functionalization catalysis
Arnold, Polly L.,Sanford, Melanie S.,Pearson, Stephen M.
, p. 13912 - 13913 (2009)
(Chemical Equation Presented) A PdIV complex that represents a viable catalytic intermediate in Pd-catalyzed C-H bond halogenation reactions has been isolated and structurally characterized. It contains the first examples of both a PdIV NHC bond and a PdIV alkoxide bond and serves as a precatalyst for C-H bond halogenation. As such, this represents a new class of tunable supporting ligand systems in PdIV catalysis.
Selective N -Chelation-directed C-H activation reactions catalyzed by pd(II) nanoparticles supported on multiwalled carbon nanotubes
Korwar, Sudha,Brinkley, Kendra,Siamaki, Ali R.,Gupton, B. Frank,Ellis, Keith C.
, p. A1782 - A1785 (2015)
N-Chelation-directed C-H activation reactions that utilize the Pd(II)/Pd(IV) catalytic cycle have been previously reported. To date, these reactions employ only homogeneous palladium catalysts. The first use of a solid-supported Pd(II) catalyst [Pd(II) nanoparticles on multiwalled carbon nanotubes, Pd(II)/MWCNT] to carry out N-chelation-directed C-H to C-O, C-Cl, and C-Br transformations is reported. The results presented demonstrate that the solid-supported Pd(II)/MWCNT catalyst can effectively catalyze C-H activation reactions using the Pd(II)/Pd(IV) catalytic cycle.
Structure–activity comparison in palladium–N–heterocyclic carbene (NHC) catalyzed arene C[sbnd]H activation- functionalization
Mondal, Moumita,Choudhury, Joyanta
, p. 451 - 457 (2017)
A simple and efficient C[sbnd]H activation catalyst was identified through a model structure-activity screening applied to a noncooperative, nonsymmetric bimetallic palladium(II)-N-heterocyclic carbene complex. Mechanistic studies based on kinetics and DOSY NMR spectroscopy provided the origin of the higher efficiency of the identified catalyst.
Manipulating MLCT transition character with ppy-type four-coordinate organoboron skeleton for highly efficient long-wavelength Ir-based phosphors in organic light-emitting diodes
Deng, Xuming,Feng, Zhao,Sun, Yuanhui,Wu, Zhaoxin,Yang, Xiaolong,Yu, Yue,Zhong, Daokun,Zhou, Guijiang
, p. 12650 - 12660 (2021)
Inspired by the intriguing optoelectronic characteristics of the 2-phenylpyridine-type (ppy-type) four-coordinate organoboron skeleton, we envisage a molecular design strategy by manipulating the MLCT transition character to develop high-performance long-wavelength Ir-based phosphors with a ppy-type four-coordinate organoboron skeleton for organic light-emitting diodes (OLEDs). Three ppy-type cyclometalated Ir(iii) complexes are successfully prepared.IrOBNandIrPBNexhibit the expected long-wavelength phosphorescent emission at 620 and 604 nm, respectively, due to the electron-accepting ability of the pyridine coordinated with the boron atom (pyd(B)) in extending the π-conjugated length for the LUMO, thus leading to stabilization of the LUMO. Interestingly,IrMBNshows a green phosphorescence at 514 nm. The more electron-deficient pyd(B) inIrMBNleads to a reorganized and localized LUMO distribution pattern mainly on pyd(B) rather than the pyridine coordinated with the Ir atom (pyd(Ir)), shortening the π-conjugation length for the LUMO, hence resulting in an elevated LUMO. Benefiting from the high rigidity of the ppy-type four-coordinate organoboron skeleton, these three ppy-type cyclometalated Ir(iii) complexes show high PLQY (ca.0.6-1). Beneficially, we can achieve impressive electroluminescence (EL) performance based onIrPBNwith the highest efficiencies of a maximum external quantum efficiency (ηext) of 26.0%, a maximum current efficiency (ηL) of 42.0 cd A?1, and a maximum power efficiency (ηP) of 38.5 lm W?1, respectively. All these excellent results convincingly demonstrate the effectiveness of our molecular design strategy and the great potential of the ppy-type four-coordinate organoboron skeleton in developing high-performance Ir-based phosphors.
Chelating Bis-N-heterocyclic Carbene-Palladium(II) Complexes for Oxidative Arene C-H Functionalization
Desai, Sai Puneet,Mondal, Moumita,Choudhury, Joyanta
, p. 2731 - 2736 (2015)
Bis-N-heterocyclic carbene (NHC)-chelated palladium(II) complexes have been synthesized, characterized fully including single-crystal X-ray structural analyses, and utilized for the first time toward catalytic oxidative C-H functionalization of arenes with PhI(OAc)2 and N-bromosuccinimide. (Figure Presented).
Hypercrosslinked Polymer Platform-Anchored Single-Site Heterogeneous Pd-NHC Catalysts for Diverse C-H Functionalization
Mandal, Tanmoy,Mondal, Moumita,Choudhury, Joyanta
supporting information, p. 2443 - 2449 (2021/08/03)
We demonstrate a new class of hypercrosslinked polymer (HCP) platform-Anchored single-site heterogenized Pd-NHC catalysts for multipurpose C-H functionalization reactions. This new class is represented by a set of three catalysts, viz., HCP-B-MeNHC-Pd, HCP-B-BnNHC-Pd, and HCP-TPM-MeNHC-Pd, having a variation on the structural feature of the anchoring polymeric platform. All three catalysts were fully characterized via diverse solid-state characterization and analytical techniques such as X-ray photoelectron spectroscopy, 13C cross-polarization magic-Angle-spinning nuclear magnetic resonance, field-emission scanning electron microscopy, energy-dispersive X-ray analysis, thermogravimetric analysis, and inductively coupled plasma-optical emission spectrometry. Three types of regularly practiced and very useful C-H functionalization reactions, viz., C-H halogenation, acetoxylation, and arylation, are tested with the new catalysts and found to be highly compatible and successful. With the HCP-TPM-MeNHC-Pd catalyst, up to 85, 75, and 70% yields of the functionalized products were achieved for the halogenation, acetoxylation, and arylation reactions, respectively. Demanding attributes such as enhanced activity, heterogeneity, and recyclability are offered by this new system, making it a promising candidate in the field of heterogeneous C-H functionalization, where only a few efficient catalysts are available.
