Mechanistic Aspects of Transition‐Metal‐Catalyzed Olefin Epoxidation from Density Functional Studies

2000 ◽  
pp. 601-619 ◽  
Author(s):  
Notker Rösch ◽  
Philip Gisdakis ◽  
Ilya V. Yudanov ◽  
Cristiana Di Valentin
Keyword(s):  
Transition Metal ◽  
Density Functional ◽  
Olefin Epoxidation ◽  
Functional Studies ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

ChemInform Abstract: Mechanistic Aspects of Transition Metal Catalyzed Olefin Epoxidation from Density Functional Studies

ChemInform ◽  
2010 ◽  
Vol 32 (27) ◽  
pp. no-no
Author(s):  
Notker Rosch ◽  
Philip Gisdakis ◽  
Ilya V. Yudanov ◽  
Cristiana Di Valentin
Keyword(s):  
Transition Metal ◽  
Density Functional ◽  
Olefin Epoxidation ◽  
Functional Studies ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

scholarly journals Role of Pyridine Nitrogen in Palladium-Catalyzed Imine Hydrolysis: A Case Study of (E)-1-(3-bromothiophen-2-yl)-N-(4-methylpyridin-2-yl)methanimine

Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2609 ◽  
Author(s):  
Ahmad ◽  
Rasool ◽  
Rizwan ◽  
Altaf ◽  
Rashid ◽  
...  
Keyword(s):  
Schiff Base ◽  
Transition Metal ◽  
Density Functional ◽  
Theoretical Calculations ◽  
Coupling Reaction ◽  
Suzuki Coupling Reaction ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed ◽  
Hydrolysis Of ◽  
Insight Into

In the present study, 4-methylpyridin-2-amine was reacted with 3-bromothiophene-2-carbaldehyde and the Schiff base (E)-1-(3-bromothiophen-2-yl)-N-(4-methylpyridin-2-yl)methanimine was obtained in a 79% yield. Coupling of the Schiff base with aryl/het-aryl boronic acids under Suzuki coupling reaction conditions, using Pd(PPh3)4 as catalyst, yielded products with the hydrolysis of the imine linkages (5a–5k, 6a–6h) in good to moderate yields. To gain mechanistic insight into the transition metal-catalyzed hydrolysis of the compounds, density functional theory (DFT) calculations were performed. The theoretical calculations strongly supported the experiment and provided an insight into the transition metal-catalyzed hydrolysis of imines.

Development of transition-metal-catalyzed cycloaddition reactions leading to polycarbocyclic systems

2011 ◽  
Vol 83 (3) ◽  
pp. 495-506 ◽  
Author(s):  
Moisés Gulías ◽  
Fernando López ◽  
José L. Mascareñas
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Dft Calculations ◽  
Density Functional ◽  
Conjugated Dienes ◽  
Ni Catalysts ◽  
Functional Theory ◽  
Different Types ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

We present a compilation of methodologies developed in our laboratories to assemble polycyclic structures containing small- and medium-sized cycles, relying on the use of transition-metal-catalyzed (TMC) cycloadditions. First, we discuss the use of alkylidenecyclopropanes (ACPs) as 3C-atom partners, in particular in their Pd-catalyzed (3 + 2) cycloadditions with alkynes, alkenes, and allenes, reactions that lead to cyclopentane-containing polycyclic products in excellent yields. Then, we present the expansion of this chemistry to a (4 + 3) annulation with conjugated dienes, and to inter- and intramolecular (3 + 2 + 2) cycloadditions using external alkenes as additional 2C-π-systems. These reactions allow the preparation of different types of polycyclic structures containing cycloheptene rings, the topology of the products depending on the use of Pd or Ni catalysts. Finally, we include our more recent discoveries on the development of (4 + 3) and (4 + 2) intramolecular cyclo-additions of allenes and dienes, promoted by Pt and Au catalysts, and discuss mechanistic insights supported by experimental and density functional theory (DFT) calculations. An enantioselective version of the (4 + 2) cycloaddition with phosphoramidite Au(I) catalysts is also presented.

DFT Study of the Mechanisms of Transition-Metal-Catalyzed Reductive Coupling Reactions

2020 ◽  
Vol 24 (12) ◽  
pp. 1367-1383
Author(s):  
Yuling Wang ◽  
Qinghua Ren
Keyword(s):  
Transition Metal ◽  
Density Functional ◽  
Single Point ◽  
Oxidative Addition ◽  
Density Functional Theory Calculations ◽  
Reductive Elimination ◽  
Coupling Reactions ◽  
Reductive Coupling ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

The mechanism studies of transition-metal-catalyzed reductive coupling reactions investigated using Density Functional Theory calculations in the recent ten years have been reviewed. This review introduces the computational mechanism studies of Ni-, Pd-, Cu- and some other metals (Rh, Ti and Zr)-catalyzed reductive coupling reactions and presents the methodology used in these computational mechanism studies. The mechanisms of the transition- metal-catalyzed reductive coupling reactions normally include three main steps: oxidative addition; transmetalation; and reductive elimination or four main steps: the first oxidative addition; reduction; the second oxidative addition; and reductive elimination. The ratelimiting step is most likely the final reductive elimination step in the whole mechanism. Currently, the B3LYP method used in DFT calculations is the most popular choice in the structural geometry optimizations and the M06 method is often used to carry out single-point calculations to refine the energy values. We hope that this review will stimulate more and more experimental and computational combinations and the computational chemistry will significantly contribute to the development of future organic synthesis reactions.

Chelation-assisted transition metal-catalysed C–H chalcogenylations

2020 ◽  
Vol 7 (8) ◽  
pp. 1022-1060 ◽  
Author(s):  
Wenbo Ma ◽  
Nikolaos Kaplaneris ◽  
Xinyue Fang ◽  
Linghui Gu ◽  
Ruhuai Mei ◽  
...  
Keyword(s):  
Transition Metal ◽  
Recent Advances ◽  
Site Selectivity ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

This review summarizes recent advances in C–S and C–Se formations via transition metal-catalyzed C–H functionalization utilizing directing groups to control the site-selectivity.

Monodentate Trialkylphosphines: Privileged Ligands in Metal-catalyzed Crosscoupling Reactions

2020 ◽  
Vol 24 (3) ◽  
pp. 231-264 ◽  
Author(s):  
Kevin H. Shaughnessy
Keyword(s):  
Transition Metal ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Aryl Bromides ◽  
Wide Range ◽  
Sterically Demanding ◽  
Transition Metal Catalyzed ◽  
Catalyzed Reactions ◽  
Metal Catalyzed

Phosphines are widely used ligands in transition metal-catalyzed reactions. Arylphosphines, such as triphenylphosphine, were among the first phosphines to show broad utility in catalysis. Beginning in the late 1990s, sterically demanding and electronrich trialkylphosphines began to receive attention as supporting ligands. These ligands were found to be particularly effective at promoting oxidative addition in cross-coupling of aryl halides. With electron-rich, sterically demanding ligands, such as tri-tertbutylphosphine, coupling of aryl bromides could be achieved at room temperature. More importantly, the less reactive, but more broadly available, aryl chlorides became accessible substrates. Tri-tert-butylphosphine has become a privileged ligand that has found application in a wide range of late transition-metal catalyzed coupling reactions. This success has led to the use of numerous monodentate trialkylphosphines in cross-coupling reactions. This review will discuss the general properties and features of monodentate trialkylphosphines and their application in cross-coupling reactions of C–X and C–H bonds.

Transition-Metal-Catalyzed Oxidative and Decarboxylative Acylations through sp2 C-H Bond Activation

2015 ◽  
Vol 20 (5) ◽  
pp. 471-511 ◽  
Author(s):  
Satyasheel Sharma ◽  
Neeraj Kumar Mishra ◽  
Youngmi Shin ◽  
In Su Kim
Keyword(s):  
Transition Metal ◽  
Bond Activation ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

Chemistry of Unsymmetrical C1-Substituted Oxabenzonorbornadienes

2021 ◽  
Vol 17 ◽  
Author(s):  
Austin Pounder ◽  
Angel Ho ◽  
Matthew Macleod ◽  
William Tam
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Substituent Effects ◽  
Face Selectivity ◽  
Transition Metal Catalyzed ◽  
Catalyzed Reactions ◽  
Metal Catalyzed ◽  
Synthetic Intermediate

: Oxabenzonorbornadiene (OBD) is a useful synthetic intermediate which can be readily activated by transition metal complexes with great face selectivity due to its dual-faced nature and intrinsic angle strain on the alkene. To date, the understanding of transition-metal catalyzed reactions of OBD itself has burgeoned; however, this has not been the case for unsymmetrical OBDs. Throughout the development of these reactions, the nature of C1-substituent has proven to have a profound effect on both the reactivity and selectivity of the outcome of the reaction. Upon substitution, different modes of reactivity arise, contributing to the possibility of multiple stereo-, regio-, and in extreme cases, constitutional isomers which can provide unique means of constructing a variety of synthetically useful cyclic frameworks. To maximize selectivity, an understanding of bridgehead substituent effects is crucial. To that end, this review outlines hitherto reported examples of bridgehead substituent effects on the chemistry of unsymmetrical C1-substituted OBDs.

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