scholarly journals Direct conjugate alkylation of α,β-unsaturated carbonyls by TiIII-catalysed reductive umpolung of simple activated alkenes

2016 ◽  
Vol 14 (24) ◽  
pp. 5673-5682 ◽  
Author(s):  
Plamen Bichovski ◽  
Thomas M. Haas ◽  
Manfred Keller ◽  
Jan Streuff
Keyword(s):  
Title Reaction ◽  
Unsaturated Carbonyls

The title reaction leads to 1,6-difunctionalized products without the requirement of premetallated reagents. Details on scope, selectivity and mechanism are reported.

Cw CO2 laser driven oxidation of some perhalogenocycloalkenes

1991 ◽  
Vol 56 (2) ◽  
pp. 398-405 ◽  
Author(s):  
Josef Pola ◽  
Jaroslav Včelák ◽  
Zdeněk Chvátal
Keyword(s):  
Co2 Laser ◽  
Total Pressure ◽  
Diels Alder ◽  
Title Reaction ◽  
Consecutive Reactions ◽  
Cw Co2 Laser

The title reaction of hexafluorocyclobutene, 1,2-dichloro-3,3,4,4-tetrafluorocyclobutene and decafluorocyclohexene studied at total pressure 13.3 and 16 kPa yield oxalyl halides COX.COX (X = F, Cl) and C2F4 that undergo consecutive reactions to COF2, CO and X2. The oxidation of decafluorocyclohexene is preceded by retro-Diels-Alder decomposition affording hexafluorocyclobutene and C2F4. Two alternative mechanisms for the oxidation of the cyclobutenes are presented, one involving a novel cleavage of intermediary bicyclic dioxetanes. The decomposition of oxalyl fluoride into COF2 and CO is favored over its oxidation.

Aliphatic Carboxylic Acid as Hydrogen-Bond Donor for Converting CO2 and Epoxide into Cyclic Carbonate under Mild Conditions

2021 ◽  
Author(s):  
Zheng Wang ◽  
Yajun Wang ◽  
Qianjie Xie ◽  
Zhiying Fan ◽  
Yehua Shen
Keyword(s):  
Hydrogen Bond ◽  
Carboxylic Acid ◽  
Value Added ◽  
Cyclic Carbonate ◽  
Hydrogen Bond Donor ◽  
Title Reaction ◽  
Aliphatic Carboxylic Acid ◽  
Mild Conditions ◽  
Atmospheric Carbon

The coupling of CO2 and epoxide is promising way to reduce atmospheric carbon by converting it into value-added cyclic carbonate. Pursuing efficient catalysts is highly attractive for the title reaction....

scholarly journals Hydrogenation of CO2 Promoted by Silicon-Activated H2S: Origin and Implications

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 50
Author(s):  
Xing Liu
Keyword(s):  
Low Temperatures ◽  
Underlying Mechanism ◽  
Reactive Species ◽  
Co2 Hydrogenation ◽  
Usual Method ◽  
Title Reaction ◽  
Hydrogenation Of Co2 ◽  
Hydrogenation Reactions

Unlike the usual method of COx (x = 1, 2) hydrogenation using H2 directly, H2S and HSiSH (silicon-activated H2S) were selected as alternative hydrogen sources in this study for the COx hydrogenation reactions. Our results suggest that it is kinetically infeasible for hydrogen in the form of H2S to transfer to COx at low temperatures. However, when HSiSH is employed instead, the title reaction can be achieved. For this approach, the activation of CO2 is initiated by its interaction with the HSiSH molecule, a reactive species with both a hydridic Hδ− and protonic Hδ+. These active hydrogens are responsible for the successive C-end and O-end activations of CO2 and hence the final product (HCOOH). This finding represents a good example of an indirect hydrogen source used in CO2 hydrogenation through reactivity tuned by silicon incorporation, and thus the underlying mechanism will be valuable for the design of similar reactions.

scholarly journals Gas-phase reactivity of acyclic α,β-unsaturated carbonyls towards ozone

2021 ◽  
Vol 23 (5) ◽  
pp. 3455-3466
Author(s):  
Jan Niklas Illmann ◽  
Iulia Patroescu-Klotz ◽  
Peter Wiesen
Keyword(s):  
Gas Phase ◽  
Unsaturated Carbonyls

This work evaluates different approaches to discuss the reactivity of α,β-unsaturated carbonyls towards ozone comparative to alkene analogues.

Selective oxidation of benzyl alcohol to benzaldehyde with H2O2 in water on epichlorohydrin-modified Fe3O4 microspheres

2015 ◽  
Vol 39 (6) ◽  
pp. 4924-4932 ◽  
Author(s):  
Shiwei Xiao ◽  
Chuntao Zhang ◽  
Rong Chen ◽  
Fengxi Chen
Keyword(s):  
Catalytic Activity ◽  
Benzyl Alcohol ◽  
Selective Oxidation ◽  
Title Reaction ◽  
Enhancing Effect ◽  
Oxidation Of Benzyl Alcohol ◽  
Fe3o4 Microspheres

The enhancing effect of modification by epichlorohydrin on the catalytic activity of Fe3O4 microspheres in the title reaction was theoretically and experimentally confirmed.

Transformation of 1-Butene over Synthetic Zeolites

1992 ◽  
Vol 57 (4) ◽  
pp. 869-881 ◽  
Author(s):  
Italo Ferino ◽  
Roberto Monaci ◽  
Vincenzo Solinas ◽  
Lucio Forni ◽  
Antonio Rivoldini ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Continuous Flow ◽  
Liquid Mixture ◽  
Isomerization Reaction ◽  
Reaction Conditions ◽  
Title Reaction ◽  
Y Zeolites ◽  
Temperature Range ◽  
Flow Microreactor ◽  
Synthetic Zeolites

The behaviour of several zeolites as catalysts for the title reaction has been investigated by means of a continuous flow microreactor. Runs performed at atmospheric pressure indicated that at 423 K the completely protonic forms of the zeolites catalyze just the isomerization reaction. In the case of Y zeolites, oligomerization occurs only over the partially decationated samples, in the temperature range between 373 and 423 K and W/F between 0.2 and 22 gcath/g1-but, to an extent which depends on the reaction conditions. Most of the catalysts were tested also under pressure (4.05 MPa) at 423 K. The protonic forms of Y and ZSM-5 zeolites seem promising catalysts in terms of both conversion and selectivity to oligomers. The 1-olefins account for 30% of the entire olefinic mixture. The octenes, which account for 70% of the liquid mixture, are mostly formed of dimethylhexenes. Trimers are also formed during the reaction and, in the very particular case of H[B]ZSM-5, tetramers are produced.

THE STEREODYNAMICS STUDY OF THE C(3P) + OH (X2 Π) → CO(X1Σ+) + H(2S) REACTION

2010 ◽  
Vol 09 (05) ◽  
pp. 935-943 ◽  
Author(s):  
PENG SONG ◽  
YONG-HUA ZHU ◽  
JIAN-YONG LIU ◽  
FENG-CAI MA
Keyword(s):  
Angular Momentum ◽  
Cross Sections ◽  
Collision Energy ◽  
Energy Surface ◽  
Center Of Mass ◽  
Title Reaction ◽  
High Collision Energy ◽  
Dependency Relationship ◽  
Energy Dependency ◽  
Mass Frame

The stereodynamics of the title reaction on the ground electronic state X2A' potential energy surface (PES)1 has been studied using the quasiclassical trajectory (QCT) method. The commonly used polarization-dependent differential cross-sections (PDDCSs) of the product and the angular momentum alignment distribution, P(θr) and P(Φr), are generated in the center-of-mass frame using QCT method to gain insight of the alignment and orientation of the product molecules. Influence of collision energy on the stereodynamics is shown and discussed. The results reveal that the distribution of P(θr) and P(Φr) is sensitive to collision energy. The PDDCSs exhibit different collision energy dependency relationship at low and high collision energy ranges.

scholarly journals Phosphite-Mediated Reductive Cross-Coupling of Isatins and Nitro­styrenes

Synthesis ◽  
2017 ◽  
Vol 49 (12) ◽  
pp. 2663-2676 ◽  
Author(s):  
Somayeh Motevalli ◽  
Jeffrey Johnson
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Reductive Coupling ◽  
Title Reaction ◽  
Dimethyl Phosphite ◽  
Mild Conditions ◽  
Michael Type Addition

A new reductive coupling reaction between N-alkylisatins, dimethyl phosphite, and nitrostyrenes has been developed. The reaction relies on Pudovik addition, subsequent phosphonate–phosphate rearrangement, and Michael-type addition of a transient carbanion on the indolinone with β-nitrostyrenes. This protocol introduces a convenient and versatile method for the construction of polyfunctionalized tertiary phosphates under mild conditions. Chiral general bases catalyze the title reaction with promising levels of enantioselectivity.

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