896-65-1Relevant academic research and scientific papers
Stoichiometric C=O bond oxidative addition of benzophenone by a discrete radical intermediate to form a cobalt(I) carbene
Marquard, Seth L.,Bezpalko, Mark W.,Foxman, Bruce M.,Thomas, Christine M.
, p. 6018 - 6021 (2013)
Single electron transfer from the ZrIIICo0 heterobimetallic complex (THF)Zr(MesNPiPr2) 3Co-N2 (1) to benzophenone was previously shown to result in the isobenzopinacol product [(Ph2CO)Zr(MesNPiPr 2)3Co-N2]2 (2) via coupling of two ketyl radicals. In this work, thermolysis of 2 in an attempt to favor a monomeric ketyl radical species unexpectedly led to cleavage of the C-O bond to generate a Zr/Co μ-oxo species featuring an unusual terminal Co=CPh 2 carbene linkage, (η2-MesNPiPr 2)Zr(μ-O)(MesNPiPr2)2Co=CPh 2 (3). This complex was characterized structurally and spectroscopically, and its electronic structure is discussed in the context of density functional theory calculations. Complex 3 was also shown to be active toward carbene group transfer (cyclopropanation), and silane addition to 3 leads to PhSiH2O-Zr(MesNPiPr2)3Co-N 2 (5) via a proposed Co-alkyl bond homolysis route.
Electrochemical Ring-Opening Dicarboxylation of Strained Carbon-Carbon Single Bonds with CO2: Facile Synthesis of Diacids and Derivatization into Polyesters
Liao, Li-Li,Wang, Zhe-Hao,Cao, Ke-Gong,Sun, Guo-Quan,Zhang, Wei,Ran, Chuan-Kun,Li, Yiwen,Chen, Li,Cao, Guang-Mei,Yu, Da-Gang
supporting information, p. 2062 - 2068 (2022/02/10)
Diacids are important monomers in the polymer industry to construct valuable materials. Dicarboxylation of unsaturated bonds, such as alkenes and alkynes, with CO2 has been demonstrated as a promising synthetic method. However, dicarboxylation of C-C single bonds with CO2 has rarely been investigated. Herein we report a novel electrochemical ring-opening dicarboxylation of C-C single bonds in strained rings with CO2. Structurally diverse glutaric acid and adipic acid derivatives were synthesized from substituted cyclopropanes and cyclobutanes in moderate to high yields. In contrast to oxidative ring openings, this is also the first realization of an electroreductive ring-opening reaction of strained rings, including commercialized ones. Control experiments suggested that radical anions and carbanions might be the key intermediates in this reaction. Moreover, this process features high step and atom economy, mild reaction conditions (1 atm, room temperature), good chemoselectivity and functional group tolerance, low electrolyte concentration, and easy derivatization of the products. Furthermore, we conducted polymerization of the corresponding diesters with diols to obtain a potential UV-shielding material with a self-healing function and a fluorine-containing polyester, whose performance tests showed promising applications.
Proton or Carbene Transfer? On the Dark and Light Reaction of Diazoalkanes with Alcohols
Empel, Claire,He, Feifei,Jana, Sripati,Koenigs, Rene M.,Pei, Chao
, (2022/02/21)
The formal alkylation reaction of OH groups with diazoalkanes under catalyst-free reaction conditions finds broad application in organic synthesis. However, even today, this reaction is mainly limited to the use of diazomethane as reaction partner. In thi
Stable group 8 metal porphyrin mono- And bis(dialkylcarbene) complexes: Synthesis, characterization, and catalytic activity
Che, Chi-Ming,Huang, Jie-Sheng,Low, Kam-Hung,Wan, Qingyun,Wang, Hai-Xu,Zhang, Jun-Long,Zhou, Cong-Ying
, p. 2243 - 2259 (2020/03/11)
Alkyl-substituted carbene (CHR or CR2, R = alkyl) complexes have been extensively studied for alkylcarbene (CHR) ligands coordinated with high-valent early transition metal ions (a.k.a. Schrock carbenes or alkylidenes), yet dialkylcarbene (CR2) complexes remain less developed with bis(dialkylcarbene) species being little (if at all) explored. Herein, several group 8 metal porphyrin dialkylcarbene complexes, including Fe- and Ru-mono(dialkylcarbene) complexes [M(Por)(Ad)] (1a,b, M = Fe, Por = porphyrinato dianion, Ad = 2-adamantylidene; 2a,b, M = Ru) and Os-bis(dialkylcarbene) complexes [Os(Por)(Ad)2] (3a-c), are synthesized and crystallographically characterized. Detailed investigations into their electronic structures reveal that these complexes are formally low-valent M(ii)-carbene in nature. These complexes display remarkable thermal stability and chemical inertness, which are rationalized by a synergistic effect of strong metal-carbene covalency, hyperconjugation, and a rigid diamondoid carbene skeleton. Various spectroscopic techniques and DFT calculations suggest that the dialkylcarbene Ad ligand is unique compared to other common carbene ligands as it acts as both a potent σ-donor and π-acceptor; its unique electronic and structural features, together with the steric effect of the porphyrin macrocycle, make its Fe porphyrin complex 1a an active and robust catalyst for intermolecular diarylcarbene transfer reactions including cyclopropanation (up to 90% yield) and X-H (X = S, N, O, C) insertion (up to 99% yield) reactions.
Rhodium-Catalyzed Arylation of Cyclopropenes Based on Asymmetric Direct Functionalization of Three-Membered Carbocycles
Dian, Longyang,Marek, Ilan
supporting information, p. 3682 - 3686 (2018/03/06)
A variety of highly diastereo- and enantiomerically enriched arylcyclopropanes is obtained through the asymmetric rhodium-catalyzed arylation reaction of achiral nonfunctionalized cyclopropene derivatives with commercially available aryl boronic acids in the presence of (R,S)-Josiphos.
Iron-catalyzed synthesis of cyclopropanes by in situ generation and decomposition of electronically diversified diazo compounds
Allouche, Emmanuelle M. D.,Al-Saleh, Afnan,Charette, André B.
supporting information, p. 13256 - 13259 (2018/12/11)
The modular synthesis of a variety of trans 1,2-disubstituted cyclopropanes in a safe and user-friendly one-pot iron-catalyzed cyclopropanation reaction is described. Easily synthesized N-nosylhydrazones are used as diazo precursors, allowing the in situ generation of electron-rich diazo compounds under mild reaction conditions and their direct participation in the cyclopropanation reaction.
Hypervalent-iodine(iii) oxidation of hydrazones to diazo compounds and one-pot nickel(ii)-catalyzed cyclopropanation
Liu, Haixuan,Wei, Yunyang,Cai, Chun
, p. 674 - 678 (2016/01/12)
A one-pot process for the catalytic cyclopropanation of various alkenes with unsubstituted hydrazones is described. Iodosobenzene (Ph = O) was found to be a competent oxidant of hydrazones to diazo compounds. Ni(OH)2 was chosen as an effective and cheap metal catalyst. The cyclopropane products can be generated efficiently (5 min-4 h) in moderate to good yields (42-91%) under mild (80°C) and neat conditions.
Copper(I)-catalyzed carbometalation of nonfunctionalized cyclopropenes using organozinc and grignard reagents
Nakano, Takeo,Endo, Kohei,Ukaji, Yutaka
supporting information, p. 671 - 675 (2015/03/14)
A highly efficient method was developed for the copper(I)-catalyzed carbometalation of various nonfunctionalized and functionalized cyclopropenes. Electrophilic trapping of the cyclopropylmetal intermediates gave multifunctionalized cyclopropanes.
DIKETIMINATO CU(I) AND CO(I) CARBENE CATALYSTS, AND CYCLOPROPANATION METHODS USING THEM
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Page/Page column 56, (2008/06/13)
The present invention described herein employs employs Cu(I) complexes of an electron-rich, bidentate N,N-donor ligand (P-diketiminates) that react with both heteroatomcontaining a-substituted diazomethanes and ary1diazomethanes to yield a unique metal-carbene complex stabilized by two metal fragments that selectively reacts with alkenes. These examples are the first of isolable Cu-carbene complexes that react with alkenes to give cyclopropanes. Furthermore, electron-rich, bidentate N,N-donor ligands can be designed to impart stereo- and enantio-selectivity in the cyclopropanation of alkenes with diazoalkanes.
Discrete bridging and terminal copper carbenes in copper-catalyzed cyclopropanation
Dai, Xuliang,Warren, Timothy H.
, p. 10085 - 10094 (2007/10/03)
The Cu(I)/ β-diketiminate [Me2NN]Cu(η2- ethylene) (2) catalyzes the cyclopropanation of styrene with N 2CPh2 to give 1,1,2-triphenylcyclopropane in 67% yield. Addition of N2CPh2 to 2 equiv of 2 allows for the isolation of the dicopper carbene {[Me2NN]Cu}2(μ- CPh2) (3) in which the diphenylcarbene moiety is symmetrically bound between two [Me2NN]Cu fragments (Cu-C = 1,922(4) and 1.930(4) A) with a Cu-Cu separation of 2.4635(7) A. In toluene-d8 solution, 3 reversibly dissociates a [Me2NN]Cu fragment to give [Me2NN]Cu(toluene) and the terminal carbene [Me2NN]Cu= CPh2, Dicopper carbene 3 reacts with 3 equiv of styrene to give 1,1,2-triphenylcyclopropane and 2 equiv of [Me2NN] Cu(η2-styrene) within minutes, DFT studies with simplified ligands indicate a stronger Cu-C π-back-bonding interaction from two Cu(I) centers to the carbene acceptor orbital in a dicopper carbene than that present in a monocopper carbene. Nonetheless, the terminal carbene [Me 3NN]Cu=CPh2 (8) that possesses a p-methyl group on each β-diketiminato N-aryl ring may be isolated and exhibits a shortened Cu-C distance of 1,834(3) A, The stoichiometric cyclopropanation of styrene by 8 in 1,4-dioxane is first-order in both copper carbene 8 and styrene with activation parameters ΔH? = 10,4(3) kcal/mol and ΔS? = -32,3(9) cal/mol·K. In 1,4-dioxane, 8 decomposes to Ph 2C=CPh2 via first-order kinetics with activation parameters ΔH? = 21(1) kcal/mol and ΔS? = -8(3) cal/mol·K. Arene solutions of thermally sensitive terminal carbene 8 decompose to [Me3NN]-Cu(arene), which reacts with 8 still present in solution to give the more thermally stable {[Me3NN]Cu} 2-(μ-CPh2).
