Iron-Promoted C–C Bond Cleavage of 1,3-Diketones: A Route to 1,2-Diketones under Mild Reaction Conditions

2011 ◽  
Vol 76 (14) ◽  
pp. 5732-5737 ◽  
Author(s):  
Lehao Huang ◽  
Kai Cheng ◽  
Bangben Yao ◽  
Yongju Xie ◽  
Yuhong Zhang
Keyword(s):  
Bond Cleavage ◽  
Reaction Conditions

scholarly journals Selective C-N σ Bond Cleavage in Azetidinyl Amides under Transition Metal-Free Conditions

Molecules ◽  
2019 ◽  
Vol 24 (3) ◽  
pp. 459 ◽  
Author(s):  
Hengzhao Li ◽  
Zemin Lai ◽  
Adila Adijiang ◽  
Hongye Zhao ◽  
Jie An
Keyword(s):  
Electron Transfer ◽  
Transition Metal ◽  
Transfer Reaction ◽  
Bond Cleavage ◽  
Electron Transfer Reaction ◽  
Amide Bond ◽  
Single Electron Transfer ◽  
Reaction Conditions ◽  
Metal Free ◽  
Single Electron Transfer Reaction

Functionalization of amide bond via the cleavage of a non-carbonyl, C-N σ bond remains under-investigated. In this work, a transition-metal-free single-electron transfer reaction has been developed for the C-N σ bond cleavage of N-acylazetidines using the electride derived from sodium dispersions and 15-crown-5. Of note, less strained cyclic amides and acyclic amides are stable under the reaction conditions, which features the excellent chemoselectivity of the reaction. This method is amenable to a range of unhindered and sterically encumbered azetidinyl amides.

Synthesis of 1-Alkyl-3-(2-oxo-2-aryl/alkyl-ethyl)indolin-2-ones through Gold/Brønsted Acid Relay Actions: Observation of Selective C=C Bond Cleavage of Enaminones

Synthesis ◽  
2017 ◽  
Vol 49 (16) ◽  
pp. 3609-3618 ◽  
Author(s):  
Yanzhong Li ◽  
Yulei Zhao ◽  
Yang Yuan ◽  
Lingkai Kong ◽  
Fangfang Zhang
Keyword(s):  
Reaction Mechanism ◽  
Bond Cleavage ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Reaction Conditions ◽  
One Pot ◽  
Esi Ms ◽  
Ms Analysis ◽  
Brönsted Acid

A novel gold(I)/Brønsted acid sequential catalyzed/promoted procedure to synthesize 1-alkyl-3-(2-oxo-2-aryl/alkyl-ethyl)indolin-2-ones under mild reaction conditions is developed. This methodology is realized by relay actions of gold and a Brønsted acid in a one-pot multistep manner. The gold(I)-catalyzed chemoselective C(sp2)-H functionalization of enaminones and Brønsted acid promoted cleavage of the C=C bond are integrated effectively. Based on the results of control experiments and ESI-MS analysis, a possible reaction mechanism is proposed.

Zur Reaktion von 1-Sila-2,4-cyclohexadien mit tert-Butyllithium/Trimethylchlorsilan / On the Reaction of 1-Sila-2,4-cyclohexadiene with tert-Butyllithium/Trimethylchlorosilane

1984 ◽  
Vol 39 (10) ◽  
pp. 1368-1374 ◽  
Author(s):  
Peter Jutzi ◽  
Gabriele Berg ◽  
Cornelius Otto ◽  
Thomas Wippermann
Keyword(s):  
Nucleophilic Substitution ◽  
Bond Cleavage ◽  
Lithium Hydride ◽  
Pure Form ◽  
Reaction Conditions ◽  
Carbon Bond ◽  
Nmr Data ◽  
Silicon Carbon ◽  
System 1 ◽  
C Nmr

In the system 1-sila-2,4-cyclohexadiene (l)/tert-butyllithium/trimethylchlorosilane the following reaction types have been observed: nucleophilic substitution, metallation, addition of tert-butyllithium to the diene fragment, addition of lithium hydride to the diene fragment, silicon-carbon bond cleavage, and transmetallation. The resulting products 2-11 have been characterised by their 1H and 13C NMR data; the compounds 2, 3, 6, 8 and 10 could be isolated in a pure form. The relative quantities obtained of the compounds 2-11 depend on the reaction conditions (solvent, temperature, order of addition).

ChemInform Abstract: Iron-Promoted C-C Bond Cleavage of 1,3-Diketones: A Route to 1,2-Diketones under Mild Reaction Conditions.

ChemInform ◽  
2011 ◽  
Vol 42 (48) ◽  
pp. no-no
Author(s):  
Lehao Huang ◽  
Kai Cheng ◽  
Bengben Yao ◽  
Yongju Xie ◽  
Yuhong Zhang
Keyword(s):  
Bond Cleavage ◽  
Reaction Conditions

scholarly journals Photoinduced Deaminative Borylation of Unactivated Aromatic Amines Enhanced by CO2

2021 ◽  
Author(s):  
Akira Shiozuka ◽  
Kohei Sekine ◽  
Yoichiro Kuninobu
Keyword(s):  
Aromatic Amines ◽  
Bond Cleavage ◽  
Bond Formation ◽  
Inhibitory Effect ◽  
Light Irradiation ◽  
Mechanistic Studies ◽  
Reaction Conditions ◽  
Metal Free ◽  
Stoichiometric Amount ◽  
Optimal Reaction

Herein, direct unactivated C-N borylation of aromatic amines by a photocatalyst was achieved under mild and metal-free conditions. The C-N borylation of aromatic amines with bis(pinacolato)diboron (B<sub>2</sub>pin<sub>2</sub>) proceeded in the presence of a pyrene catalyst under light irradiation (λ = 365 nm) <a>to afford desired borylated products</a> and aminoborane as a byproduct. The yield of borylated product improved under a CO<sub>2</sub> atmosphere. Reactions conducted in the presence of a stoichiometric amount of aminoborane under N<sub>2</sub> or CO<sub>2</sub> indicated that CO<sub>2</sub> reduced the inhibitory effect of aminoborane. Optimal reaction conditions were applied to a variety of aromatic amines. Mechanistic studies suggested that the C-N bond cleavage and C-B bond formation proceeded via a concerted pathway.

scholarly journals Mechanistic Insight into the Ring-Opening Polymerization of ɛ-Caprolactone and L-Lactide Using Ketiminate-Ligated Aluminum Catalysts

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1530 ◽  
Author(s):  
Lin ◽  
Jheng
Keyword(s):  
Thermal Effects ◽  
Ring Opening ◽  
Density Functional ◽  
Bond Cleavage ◽  
Ring Opening Polymerization ◽  
Catalyst Design ◽  
Reaction Conditions ◽  
Functional Theory ◽  
Cleavage Step ◽  
Insight Into

The reactivity and the reaction conditions of the ring-opening polymerization of ɛ-caprolactone (ɛ-CL) and L-lactide (LA) initiated by aluminum ketiminate complexes have been shown differently. Herein, we account for the observation by studying the mechanisms on the basis of density functional theory (DFT) calculations. The calculations show that the ring-opening polymerization of ɛ-CL and LA are rate-determined by the benzoxide insertion and the C–O bond cleavage step, respectively. Theoretical computations suggest that the reaction temperature of L–LA polymerization should be higher than that of ɛ-CL one, in agreement with the experimental data. To provide a reasonable interpretation of the experimental results and to give an insight into the catalyst design, the influence of the electronic, steric, and thermal effects on the polymerization behaviors will be also discussed in this study.

C(sp3)–H functionalizations of light hydrocarbons using decatungstate photocatalysis in flow

Science ◽  
2020 ◽  
Vol 369 (6499) ◽  
pp. 92-96 ◽  
Author(s):  
Gabriele Laudadio ◽  
Yuchao Deng ◽  
Klaas van der Wal ◽  
Davide Ravelli ◽  
Manuel Nuño ◽  
...  
Keyword(s):  
Room Temperature ◽  
High Selectivity ◽  
Bond Cleavage ◽  
Hydrogen Atom Transfer ◽  
Light Hydrocarbons ◽  
Reaction Conditions ◽  
Potential Applications ◽  
Michael Acceptors ◽  
Gaseous Hydrocarbons ◽  
Chemistry Community

Direct activation of gaseous hydrocarbons remains a major challenge for the chemistry community. Because of the intrinsic inertness of these compounds, harsh reaction conditions are typically required to enable C(sp3)–H bond cleavage, barring potential applications in synthetic organic chemistry. Here, we report a general and mild strategy to activate C(sp3)–H bonds in methane, ethane, propane, and isobutane through hydrogen atom transfer using inexpensive decatungstate as photocatalyst at room temperature. The corresponding carbon-centered radicals can be effectively trapped by a variety of Michael acceptors, leading to the corresponding hydroalkylated adducts in good isolated yields and high selectivity (38 examples).

scholarly journals Dinuclear manganese alkoxide complexes as catalysts for C–N bond cleavage of simple tertiary N,N-dialkylamides to give esters

2019 ◽  
Vol 10 (10) ◽  
pp. 2860-2868 ◽  
Author(s):  
Haruki Nagae ◽  
Takahiro Hirai ◽  
Daiki Kato ◽  
Shusei Soma ◽  
Shin-ya Akebi ◽  
...  
Keyword(s):  
Chemical Transformation ◽  
Bond Cleavage ◽  
Lone Pair ◽  
Organic Reactions ◽  
Reaction Conditions ◽  
Amide Bonds ◽  
Nitrogen Lone Pair ◽  
Tertiary Amides ◽  
Strong Acids

Amide bonds are stable due to the resonance between the nitrogen lone pair and the carbonyl moiety, and therefore the chemical transformation of amides, especially tertiary amides, involving C–N bond fission is considered one of the most difficult organic reactions, unavoidably requiring harsh reaction conditions and strong acids or bases.

scholarly journals Copper-catalyzed aerobic radical C–C bond cleavage of N–H ketimines

2015 ◽  
Vol 11 ◽  
pp. 1933-1943 ◽  
Author(s):  
Ya Lin Tnay ◽  
Gim Yean Ang ◽  
Shunsuke Chiba
Keyword(s):  
Bond Cleavage ◽  
Grignard Reagents ◽  
Radical Intermediate ◽  
Reaction Conditions ◽  
Radical Process ◽  
Radical Fragmentation ◽  
Aerobic Reaction

We report herein studies on copper-catalyzed aerobic radical C–C bond cleavage of N–H ketimines. Treatment of N–H ketimines having an α-sp3 hybridized carbon under Cu-catalyzed aerobic reaction conditions resulted in a radical fragmentation with C–C bond cleavage to give the corresponding carbonitrile and carbon radical intermediate. This radical process has been applied for the construction of oxaspirocyclohexadienones as well as in the electrophilic cyanation of Grignard reagents with pivalonitrile as a CN source.

Reaction of Borane in Tetrahydrofuran with 1,1,3,3-Tetramethyldisilazane and Cyclic Disilazanes - Competition Between N-Si and N-H Bond Cleavage

1996 ◽  
Vol 51 (12) ◽  
pp. 1707-1715 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Bernd Schwarze
Keyword(s):  
Nmr Spectra ◽  
Bond Cleavage ◽  
Reaction Conditions

Borane in tetrahydrofuran (THF-BH3/THF; 1) reacts with 1,1,3,3-tetramethyldisilazane (2a) and the cyclic disilazanes (2b), 3 (2c), 4 (2d)] first by formation of amine-borane adducts (3a - d), and then to give /μ-aminodiboranes(6) by H2 elimination (4a -,d) or cleavage of N-Si bonds (5a-d ), depending on the reaction conditions, in agreement with the results obtained for the reaction of 1 with hexamethyldisilazane. Further transformations proceed via the N,N-disilylaminoboranes 6a - d. In the case of the reaction between 1 and 2b, it proved possible to convert 4b and/or 5b quantitatively into the mixed diaminoborane 7b which served for the synthesis of N,N′,N″-tris[(2′-dimethylsilylethyl)dimethylsilyl]borazine (8b). The Si-H functions in 5b, 7b and 8b react with Co2(CO)8 to afford the respective Si-Co(CO)4 derivatives 11b - 13b. All compounds were characterized by their 1H , 11B, 13C, 14/15N and 29Si NMR spectra.

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