scholarly journals Transition metal-catalyzed [2 + 2 + 2] cycloaddition of nitrogen-linked 1,6-diynes: a straightforward route to fused pyrrolidine systems

RSC Advances ◽  
2017 ◽  
Vol 7 (69) ◽  
pp. 43716-43736 ◽  
Author(s):  
Mirzaagha Babazadeh ◽  
Somayeh Soleimani-Amiri ◽  
Esmail Vessally ◽  
Akram Hosseinian ◽  
Ladan Edjlali
Keyword(s):  
Transition Metal ◽  
High Efficiency ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

Transition metal-catalyzed [2 + 2 + 2] cycloadditions of nitrogen-linked 1,6-diynes with unsaturated motifs have recently attracted more attention from synthetic organic chemists because of their high efficiency in the construction of numerous pyrrolidine based systems.

scholarly journals Transition metal-catalyzed redox isomerization of codeine and morphine in water

RSC Advances ◽  
2014 ◽  
Vol 4 (74) ◽  
pp. 39519-39522 ◽  
Author(s):  
Antonio Bermejo Gómez ◽  
Pär Holmberg ◽  
Jan-E. Bäckvall ◽  
Belén Martín-Matute
Keyword(s):  
Transition Metal ◽  
High Efficiency ◽  
Water Soluble ◽  
Rhodium Complex ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed ◽  
Very High ◽  
Redox Isomerization

A water-soluble rhodium complex formed from commercially available [Rh(COD)(CH3CN)2]BF4 and 1,3,5-triaza-7-phosphaadamantane (PTA) catalyzes the isomerization of both codeine and morphine into hydrocodone and hydromorphone in water with very high efficiency.

Efficient synthesis strategies by application of transition metal-catalyzed carbene/nitrene insertions into C–H bonds

2014 ◽  
Vol 31 (4) ◽  
pp. 449-455 ◽  
Author(s):  
Julian Egger ◽  
Erick M. Carreira
Keyword(s):  
Transition Metal ◽  
High Efficiency ◽  
Efficient Synthesis ◽  
Total Syntheses ◽  
Transition Metal Catalyzed ◽  
Metal Catalyzed

This Highlight article provides an overview of recent total syntheses that are characterized by high efficiency and enabled through a neat application of transition metal-catalyzed insertions of carbenes and nitrenes into C–H bonds.

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.

Copper Catalysts in the Synthesis of Five-membered N-polyheterocycles

2018 ◽  
Vol 15 (7) ◽  
pp. 940-971 ◽  
Author(s):  
Navjeet Kaur
Keyword(s):  
Transition Metal ◽  
Organic Synthesis ◽  
Copper Catalysts ◽  
Research Field ◽  
Chemoselective Synthesis ◽  
Specialized Equipment ◽  
Transition Metal Catalyzed ◽  
Synthetic Methodologies ◽  
Metal Catalyzed ◽  
Traditional Approaches

Background: Due to significant biological activity associated with N-, O- and S-heterocycles, a number of reports for their synthesis have appeared in recent decades. Traditional approaches require expensive or highly specialized equipment or would be of limited use to the synthetic organic chemist due to their highly inconvenient approaches. This review summarizes the applications of copper catalysts with the emphasis on their synthetic applications for nitrogen bearing polyheterocylces. In summary, this review article describes the synthesis of a number of five-membered poly heterocyclic rings. Objective: Nowadays new approaches that employ atom-economical and efficient pathway have been developed. The researchers are following natural models to design and synthesize heterocycles. The transition metal catalyzed protocols have attracted the attention as compared to other synthetic methodologies because they use easily available substrates to build multiple substituted complicated molecules directly under mild conditions. In organic synthesis, constituted by transition metal catalyzed coupling transformations are one of the most powerful and useful protocols. The N-heterocycles are synthesized by this convenient and useful tool. Conclusion: The efficient and chemoselective synthesis of heterocycles by this technique has appeared as an important tool. This review shows a highly dynamic research field and the employment of copper catalysts in organic synthesis. Several strategies have been pointed out in the past few years, to meet more sustainable, efficient and environmentally benign chemical products and procedures. The catalytic strategies have been the focus of intense research because they avoid the use of toxic reagents. Among these catalytic strategies, highly rewarding and an important method in heterocycles synthesis is metal catalyzed synthesis.

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