Cu(I)-Bis(phosphine) Dioxides as catalysts for the Enantioselective α-Arylation of Carbonyl Compounds

Synlett ◽  
2021 ◽  
Author(s):  
Margarita Escudero-Casao ◽  
Giulia Licini ◽  
Manuel Orlandi
Keyword(s):  
Reaction Mechanism ◽  
Transition Metal ◽  
Catalytic System ◽  
Carbonyl Compounds ◽  
Research Area ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

The transition metal catalyzed α-arylation of carbonyl compounds was first reported by Buchwald and Hartwig in 1997. This transformation has been used and studied extensively over the last two decades. Enantioselective variants were also developed that allow for controlling the product stereochemistry. However, these suffer several limitations in the context of formation of tertiary stereocenters. Presented here is our group’s contribution to this research area. The chiral Cu-bis(phosphine) dioxides catalytic system that we reported allowed accessing the enantioselective α-arylation of ketones that were not suitable for this transformation before in good yields and er up to 97.5:2.5. Preliminary insight and speculation concerning the reaction mechanism involving the unusual pairing of bis(phosphine) dioxides with transition metal catalysts is also given.

scholarly journals Transition metal-catalyzed organic reactions in undivided electrochemical cells

2021 ◽  
Author(s):  
Cong Ma ◽  
Ping Fang ◽  
Dong Liu ◽  
Ke-Jin Jiao ◽  
Pei-Sen Gao ◽  
...  
Keyword(s):  
Transition Metal ◽  
Research Area ◽  
Metal Catalysts ◽  
Organic Reactions ◽  
Electrochemical Cells ◽  
Organic Electrochemistry ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

Abstract: Transition metal-catalyzed organic electrochemistry is a rapidly growing research area owing in part of the ability of metal catalysts to alter the selectivity of a given transformation. This conversion...

Directing-Group-Assisted Transition-Metal-Catalyzed Direct C–H Oxidative Annulation of Arenes with Alkynes for Facile Construction of Various Oxygen Heterocycles

Synthesis ◽  
2020 ◽  
Vol 52 (07) ◽  
pp. 993-1006 ◽  
Author(s):  
Guanghua Kuang ◽  
Guangyuan Liu ◽  
Xingxing Zhang ◽  
Naihao Lu ◽  
Yiyuan Peng ◽  
...  
Keyword(s):  
Transition Metal ◽  
Noble Metals ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Research Papers ◽  
Recent Advances ◽  
Oxygen Heterocycles ◽  
Directing Group ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

The most recent advances in the construction of oxygen heterocycles by the directing-group-assisted transition-metal-catalyzed direct oxidative annulation of arenes with diverse alkynes are summarized in this review. More than 140 recent research papers and many closely related reviews are referenced in this paper. Nine different oxygen heterocycles frameworks are discussed. Several traditional transition-metal catalysts as well as some classical non-noble metals are utilized to promote the annulation. Three plausible controlling models are disclosed to clarify the excellent regioselectivity outcomes achieved in case of unsymmetrical alkyne substrates.1 Introduction2 Coumarins3 I socoumarins and Their Analogues4 2-Pyrones and Their Analogues5 Chromones and Chroman-4-ones6 Chromenes and Isochromenes7 Fused Polycyclic Oxygen Heteroaromatics8 Benzofurans, Dihydrobenzofurans, and Furans9 Phthalides and Benzofuranones10 Benzoxepines11 Conclusion

scholarly journals Recent Advances in Transition Metal-Catalyzed Reactions of Oxabenzonorbornadiene

2019 ◽  
Vol 16 (4) ◽  
pp. 460-484 ◽  
Author(s):  
Rebecca Boutin ◽  
Samuel Koh ◽  
William Tam
Keyword(s):  
Transition Metal ◽  
Structural Features ◽  
Metal Catalysts ◽  
Single Step ◽  
Transition Metal Catalysts ◽  
Biologically Active ◽  
Transition Metal Catalyzed ◽  
Catalyzed Reactions ◽  
Metal Catalyzed ◽  
Work Done

Background: Oxabenzonorbornadiene (OBD) is a useful synthetic intermediate capable of undergoing multiple types of transformations due to three key structural features: a free alkene, a bridged oxygen atom, and a highly strained ring system. Most notably, ring-opening reactions of OBD using transition metal catalysts and nucleophiles produce multiple stereocenters in a single step. The resulting dihydronaphthalene framework is found in many natural products, which have been shown to be biologically active. Objective: This review will provide an overview of transition metal-catalyzed reactions from the past couple of years including cobalt, copper, iridium, nickel, palladium and rhodium- catalyzed reactions. In addition, the recent derivatization of OBD to cyclopropanated oxabenzonorbornadiene and its reactivity will be discussed. Conclusion: It can be seen from the review, that the work done on this topic has employed the use of many different transition metal catalysts, with many different nucleophiles, to perform various transformations on the OBD molecule. Additionally, depending on the catalyst and ligand used, the stereo and regioselectivity of the product can be controlled, with proposed mechanisms to support the understanding of such reactions. The use of palladium has also generated a cyclopropanated OBD, with reactivity similar to that of OBD. An additional reactive site exists at the distal cyclopropane carbon, giving rise to three types of ring-opened products.

Phosphorus-Containing Groups Assisted Transition Metal Catalyzed C-H Activation Reactions

2019 ◽  
Vol 23 (2) ◽  
pp. 103-135 ◽  
Author(s):  
Chun-Ni Zhou ◽  
Zi-Ang Zheng ◽  
George Chang ◽  
Yuan-Chao Xiao ◽  
Yang-Huan Shen ◽  
...  
Keyword(s):  
Transition Metal ◽  
Functional Group ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Mechanistic Study ◽  
Recent Advances ◽  
Phosphorus Containing ◽  
Directing Group ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

Over the last few decades, transition metal-catalyzed direct C-H activation with the assistance of a coordinating directing group has emerged as an atom- and stepeconomical synthetic tools to transform C–H bonds into carbon-carbon or carbonheteroatom bonds. Although the strategies involving regioselective C–H cleavage assisted by various directing groups have been extensively reviewed in the literature, we now attempt to give an overview of the recent advances on phosphorus-containing functional group assisted C-H activation reactions catalyzed by transition-metal catalysts including mechanistic study and synthetic applications. The discussion is directed towards C-H olefination, C-H activation/cyclization, C-H arylation, C-H amination, C-H hydroxylation and acetoxylation as well as miscellaneous C-H activation.

scholarly journals Silicon Grignard Reagents as Nucleophiles in Transition-Metal-Catalyzed Allylic Substitution

Synthesis ◽  
2018 ◽  
Vol 51 (01) ◽  
pp. 233-239 ◽  
Author(s):  
Weichao Xue ◽  
Martin Oestreich
Keyword(s):  
Transition Metal ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Grignard Reagents ◽  
Allylic Substitution ◽  
Substitution Reactions ◽  
Cyclic System ◽  
Leaving Group ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

A broad range of transition-metal catalysts is shown to promote allylic substitution reactions of allylic electrophiles with silicon Grignard reagents. The procedure was further elaborated for CuI as catalyst. The regioselectively is independent of the leaving group for primary allylic precursors, favoring α over γ. The stereochemical course of this allylic transposition was probed with a cyclic system, and anti-dia­stereoselectivity was obtained.

Recent Progress on the Synthesis of (Aza)indoles through Oxidative Alkyne Annulation Reactions

Synlett ◽  
2017 ◽  
Vol 28 (15) ◽  
pp. 1867-1872 ◽  
Author(s):  
Hai-Chao Xu ◽  
Zhong-Wei Hou ◽  
Zhong-Yi Mao
Keyword(s):  
Transition Metal ◽  
Recent Progress ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Powerful Method ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

The oxidative [3+2] cycloaddition of alkynes with arylamines is a powerful method for the synthesis of (aza)indoles because it employs unfunctionalized and easily available materials. Herein, recent progress in the synthesis of (aza)indoles through transition metal-catalyzed oxidative [3+2] cycloaddition is highlighted.1 Introduction2 Second-Row Transition-Metal Catalysts3 First-Row Transition-Metal Catalysts4 Summary

Recent advance in NHC-palladium catalysis for alkynes chemistry: versatile synthesis and applications

2021 ◽  
Author(s):  
Jianxiao Li ◽  
Dan He ◽  
Zidong Lin ◽  
Wanqing Wu ◽  
Huanfeng Jiang
Keyword(s):  
Transition Metal ◽  
Palladium Catalysis ◽  
Metal Catalysts ◽  
Chemical Transformations ◽  
The Past ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

During the past decades, alkynes chemistry has attracted considerable attention owing to their unique and idiographic nucleophilic and electrophilic properties in transition-metal-catalyzed chemical transformations. Among the various metal catalysts, palladium...

scholarly journals Transition Metal-Catalyzed α-Position Carbon–Carbon Bond Formations of Carbonyl Derivatives

Catalysts ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 861 ◽  
Author(s):  
Ha-Eun Lee ◽  
Dopil Kim ◽  
Ahrom You ◽  
Myung Hwan Park ◽  
Min Kim ◽  
...  
Keyword(s):  
Transition Metal ◽  
Carbonyl Compounds ◽  
Bond Formation ◽  
Chiral Ligand ◽  
Catalytic Systems ◽  
Carbon Bond ◽  
Carbonyl Derivatives ◽  
Carbon Carbon Bond ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

α-Functionalization of carbonyl compounds in organic synthesis has traditionally been accomplished via classical enolate chemistry. As α-functionalized carbonyl moieties are ubiquitous in biologically and pharmaceutically valuable molecules, catalytic α-alkylations have been extensively studied, yielding a plethora of practical and efficient methodologies. Moreover, stereoselective carbon–carbon bond formation at the α-position of achiral carbonyl compounds has been achieved by using various transition metal–chiral ligand complexes. This review describes recent advances—in the last 20 years and especially focusing on the last 10 years—in transition metal-catalyzed α-alkylations of carbonyl compounds, such as aldehydes, ketones, imines, esters, and amides and in efficient carbon–carbon bond formations. Active catalytic species and ligand design are discussed, and mechanistic insights are presented. In addition, recently developed photo-redox catalytic systems for α-alkylations are described as a versatile synthetic tool for the synthesis of chiral carbonyl-bearing molecules.

Metathetical Degradation and Depolymerization of Unsaturated Polymers

1997 ◽  
Vol 70 (3) ◽  
pp. 519-529 ◽  
Author(s):  
J. C. Marmo ◽  
K. B. Wagener
Keyword(s):  
Molecular Weight ◽  
Transition Metal ◽  
Catalytic System ◽  
Lewis Acid ◽  
Catalyst System ◽  
Metal Catalysts ◽  
Transition Metal Catalysts ◽  
Side Reactions

Abstract The employment of transition metal catalysts has been a viable route in the degradation and depolymerization of unsaturated polymers. Initially, unsaturated polymers were degraded with a catalytic system containing a transition metal and a Lewis acid cocatalyst (WCl6/SnBu4). Degradation chemistry was effective in reducing the molecular weight of the polymer, however, the classical catalyst system induces side reactions which generates ill-defined products. These side reactions were obviated by using a preformed alkylidene without a Lewis acid cocatalyst, and perfectly difunctional telechelics were synthesized.

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