Transition Metal-Catalyzed Reactions of Alkynyl Halides

2019 ◽  
Vol 16 (4) ◽  
pp. 546-582 ◽  
Author(s):  
Dina Petko ◽  
Samuel Koh ◽  
William Tam
Keyword(s):  
Transition Metal ◽  
Transition Metal Catalysts ◽  
Cycloaddition Reactions ◽  
Coupling Reactions ◽  
Silicon Carbon ◽  
Transition Metal Catalyzed ◽  
Catalyzed Reactions ◽  
Metal Catalyzed ◽  
Sonogashira Reactions ◽  
Work Done

Background: Transition metal-catalyzed reactions of alkynyl halides are a versatile means of synthesizing a wide array of products. Their use is of particular interest in cycloaddition reactions and in constructing new carbon-carbon and carbon-heteroatom bonds. Transition metal-catalyzed reactions of alkynyl halides have successfully been used in [4+2], [2+2], [2+2+2] and [3+2] cycloaddition reactions. Many carbon-carbon coupling reactions take advantage of metal-catalyzed reactions of alkynyl halides, including Cadiot-Chodkiewicz, Suzuki-Miyaura, Stille, Kumada-Corriu and Inverse Sonogashira reactions. All the methods of constructing carbon-nitrogen, carbon-oxygen, carbon-phosphorus, carbon-sulfur, carbon-silicon, carbon-selenium and carbon-tellurium bonds employed alkynyl halides. Objective: The purpose of this review is to highlight and summarize research conducted in transition metalcatalyzed reactions of alkynyl halides in recent years. The focus will be placed on cycloaddition and coupling reactions, and their scope and applicability to the synthesis of biologically important and industrially relevant compounds 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 to perform various cycloadditions, cyclizations, and couplings using alkynyl halides. The reactions involving alkynyl halides were efficient in generating both carbon-carbon and carbonheteroatom bonds. Proposed mechanisms were included to support the understanding of such reactions. Many of these reactions face retention of the halide moiety, allowing additional functionalization of the products, with some new products being inaccessible using their standard alkyne counterparts.

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.

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 reactions of carbon-heteroatom bond formation by substitution and addition processes

2005 ◽  
Vol 77 (12) ◽  
pp. 2021-2027 ◽  
Author(s):  
Irina P. Beletskaya
Keyword(s):  
Transition Metal ◽  
Triple Bond ◽  
Bond Formation ◽  
Cross Coupling ◽  
Addition Reactions ◽  
Coupling Reactions ◽  
Cross Coupling Reactions ◽  
Transition Metal Catalyzed ◽  
Catalyzed Reactions ◽  
Metal Catalyzed

Two types of transition-metal-catalyzed cross-coupling reactions, which both lead to the formation of carbon-heteroatom bonds, are considered: RX + E-H and E-X + RM. The potential of addition reactions of E-H or E-E to double or triple bond in C-E bond formation is also demonstrated.

scholarly journals Synthesis and Reactivity of Mixed Dimethylalkynylaluminum Reagents

Synthesis ◽  
2018 ◽  
Vol 51 (01) ◽  
pp. 97-106
Author(s):  
Riccardo Piccardi ◽  
Serge Turcaud ◽  
Erica Benedetti ◽  
Laurent Micouin
Keyword(s):  
Transition Metal ◽  
Special Class ◽  
Triple Bond ◽  
Lewis Acidity ◽  
Coupling Reactions ◽  
Organometallic Reagents ◽  
The Creation ◽  
Transition Metal Catalyzed ◽  
Catalyzed Reactions ◽  
Metal Catalyzed

Organoaluminum derivatives are mostly appreciated for their Lewis acidity properties, but generally not considered as reagents of choice in synthetic transformations involving the creation of C–C bonds. Among these species, dimethylalkynylaluminum reagents represent a special class of compounds, with, in many cases, unique reactivity. This review summarizes the preparation and reactivity of these organometallic reagents with a focus on their synthetic potential.1 Introduction2 Preparation of Dimethylalkynylaluminum Reagents3 Reactivity of Dimethylalkynylaluminum Reagents3.1 Reactions with Csp3 Electrophiles3.2 Reactions with Csp2 Electrophiles4 Transition-Metal-Catalyzed Reactions4.1 Addition to α,β-Unsaturated Enones4.2 Coupling Reactions5 Triple Bond Reactivity6 Conclusion

Transition Metal-Catalyzed Reactions of 3-Aza-2-oxabicyclo[2.2.1]hept-5-enes

2018 ◽  
Vol 15 (6) ◽  
pp. 762-780
Author(s):  
Katrina Tait ◽  
William Tam
Keyword(s):  
Transition Metal ◽  
Transition Metals ◽  
Bond Cleavage ◽  
Transition Metal Catalysts ◽  
Biologically Active ◽  
Diverse Range ◽  
Oxabicyclic Alkenes ◽  
Transition Metal Catalyzed ◽  
Catalyzed Reactions ◽  
Metal Catalyzed

Background: Transition metal catalysts are becoming increasingly more important in organic synthesis and are being used to catalyze novel reactions that allow for more efficient synthesis of many pharmaceuticals. Transition metal-catalyzed reactions of 3-aza-2-oxabicyco[2.2.1]hept-5-enes provide efficient synthetic pathways to generate a diverse range of biologically and synthetically useful products. 3-Aza-2- oxabicyclic alkenes undergo three main types of reactions: reductive N-O bond cleavage, C-O bond cleavage, and modification of the alkene component. Objective: The purpose of this review is to summarize and discuss the transition metal-mediated reactions of 3- aza-2-oxabicyclo[2.2.1]hept-5-enes, including the mechanisms of reactions based on the transition metal used, the different stereo- and regiochemical outcomes of reactions with this asymmetrical substrate, and the biological importance of exploring these reactions. Conclusion: It is clear from the review of the topic that a vast amount of work has been done in this area, and transition metals have been used to control the regio- and stereoselective reactions of 3-aza-2-oxabicyclic alkenes to create biologically active and synthetically useful products. The transition metal-catalyzed reactions of 3-aza-2-oxabicyclic alkenes proceed through three general reactions: through cleavage of the N-O bond, cleavage of the C-O bond, and modification of the alkene component. Without the use of transition metals, the substrate would not be activated and these reactions would not be possible. The use of transition metals opens up an array of new reactions that have the ability to create different functional groups with different regio- and stereoselectivities based on the metal and conditions used. The products made through these transition metalcatalyzed reactions can be useful as antibiotics, siderophores, and carbocyclic nucleosides such as noraristeromycin and carbocyclic polyoxin C.

scholarly journals Recent Advances in Transition-Metal-Catalyzed, Directed Aryl C–H/N–H Cross-Coupling Reactions

Synthesis ◽  
2017 ◽  
Vol 49 (20) ◽  
pp. 4586-4598 ◽  
Author(s):  
Martyn Henry ◽  
Mohamed Mostafa ◽  
Andrew Sutherland
Keyword(s):  
Transition Metal ◽  
Bond Formation ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Short Review ◽  
Coupling Reactions ◽  
Dehydrogenative Coupling ◽  
Transition Metal Catalyzed ◽  
Catalyzed Reactions ◽  
Metal Catalyzed

Amination and amidation of aryl compounds using a transition-metal-catalyzed cross-coupling reaction typically involves prefunctionalization or preoxidation of either partner. In recent years, a new class of transition-metal-catalyzed cross-dehydrogenative coupling reaction has been developed for the direct formation of aryl C–N bonds. This short review highlights the substantial progress made for ortho-C–N bond formation via transition-metal-catalyzed chelation-directed aryl C–H activation and gives an overview of the challenges that remain for directed meta- and para-selective reactions.1 Introduction2 Intramolecular C–N Cross-Dehydrogenative Coupling2.1 Nitrogen Functionality as Both Coupling Partner and Directing Group2.2 Chelating-Group-Directed Intramolecular C–N Bond Formation3 Intermolecular C–N Cross-Dehydrogenative Coupling3.1 ortho-C–N Bond Formation3.1.1 Copper-Catalyzed Reactions3.1.2 Other Transition-Metal-Catalyzed Reactions3.2 meta- and para-C–N Bond Formation4 C–N Cross-Dehydrogenative Coupling of Acidic C–H Bonds5 Conclusions

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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