Metal-mediated asymmetric alkylation using chiral N-heterocyclic carbenes derived from chiral amines

2007 ◽  
Vol 251 (5-6) ◽  
pp. 702-717 ◽  
Author(s):  
Richard E. Douthwaite
Keyword(s):  
Heterocyclic Carbenes ◽  
Chiral Amines ◽  
Asymmetric Alkylation

Aryl-substituted Triarsiranes: Synthesis and Reactivity

2020 ◽  
Author(s):  
André Schumann ◽  
Jonas Bresien ◽  
Malte Fischer ◽  
Christian Hering-Junghans
Keyword(s):  
Organic Chemistry ◽  
Electronic Structure ◽  
Heterocyclic Carbenes ◽  
Synthetic Approaches ◽  
Inorganic And Organic

Cyclotriarsanes are rare and limited synthetic approaches have hampered reactivity studies on these systems. Described in here is a scalable synthetic protocol towards (AsAr)<sub>3</sub> (Ar = Dip, 2,6-<sup>i</sup>Pr<sub>2</sub>-C<sub>6</sub>H<sub>3</sub>; Tip, 2,4,6-<sup>i</sup>Pr<sub>3</sub>-C<sub>6</sub>H<sub>2</sub>), which allowed to study their reactivity towards [Cp<sub>2</sub>Ti(C<sub>2</sub>(SiMe<sub>3</sub>)<sub>2</sub>], affording titanocene diarsene complexes and towards N-heterocyclic carbenes (NHCs) to give straightforward access to a variety of NHC-arsinidene adducts. The electronic structure of the titanium diarsene complxes has been studied and they are best described as Ti(IV) species with a doubly reduced As<sub>2</sub>Ar<sub>2</sub> ligand. These findings will make (AsAr)<sub>3</sub> valuable precursors in the synthetic inorganic and organic chemistry.

Application of Nitrogen Heterocyclic Carbenes in Organocatalysis

2020 ◽  
Vol 09 ◽  
Author(s):  
Minita Ojha ◽  
R. K. Bansal
Keyword(s):  
Asymmetric Catalysis ◽  
Building Blocks ◽  
Structural Features ◽  
Heterocyclic Carbenes ◽  
Stetter Reaction ◽  
Metal Pollutants ◽  
Synthetic Strategy ◽  
Wide Range ◽  
Benzoin Condensation ◽  
Nitrogen Heterocyclic

Background: During the last two decades, horizon of research in the field of Nitrogen Heterocyclic Carbenes (NHC) has widened remarkably. NHCs have emerged as ubiquitous species having applications in a broad range of fields, including organocatalysis and organometallic chemistry. The NHC-induced non-asymmetric catalysis has turned out to be a really fruitful area of research in recent years. Methods: By manipulating structural features and selecting appropriate substituent groups, it has been possible to control the kinetic and thermodynamic stability of a wide range of NHCs, which can be tolerant to a variety of functional groups and can be used under mild conditions. NHCs are produced by different methods, such as deprotonation of Nalkylhetrocyclic salt, transmetallation, decarboxylation and electrochemical reduction. Results: The NHCs have been used successfully as catalysts for a wide range of reactions making a large number of building blocks and other useful compounds accessible. Some of these reactions are: benzoin condensation, Stetter reaction, Michael reaction, esterification, activation of esters, activation of isocyanides, polymerization, different cycloaddition reactions, isomerization, etc. The present review includes all these examples published during the last 10 years, i.e. from 2010 till date. Conclusion: The NHCs have emerged as versatile and powerful organocatalysts in synthetic organic chemistry. They provide the synthetic strategy which does not burden the environment with metal pollutants and thus fit in the Green Chemistry.

scholarly journals Sydnone methides – a forgotten class of mesoionic compounds for the generation of anionic N‐heterocyclic carbenes

2021 ◽  
Author(s):  
Andreas Schmidt ◽  
Sebastian Mummel ◽  
Felix Lederle ◽  
Eike Hübner ◽  
Jan C. Namyslo ◽  
...  
Keyword(s):  
Heterocyclic Carbenes

Iminophosphorane-mediated regioselective umpolung alkylation reaction of α-iminoesters

2021 ◽  
Author(s):  
Yasushi Yoshida ◽  
Mayu Kukita ◽  
Kazuki Omori ◽  
Takashi Mino ◽  
Masami Sakamoto
Keyword(s):  
Asymmetric Reactions ◽  
Alkylation Reaction ◽  
Chiral Amines ◽  
Efficient Manner

Umpolung reactions of imines, especially the asymmetric reactions, have been extensively studied as they provide access to important chiral amines in an efficient manner. The reactions studied range from simple...

scholarly journals A monotopic aluminum telluride with an Al=Te double bond stabilized by N-heterocyclic carbenes

2015 ◽  
Vol 6 (1) ◽  
Author(s):  
Daniel Franz ◽  
Tibor Szilvási ◽  
Elisabeth Irran ◽  
Shigeyoshi Inoue
Keyword(s):  
Double Bond ◽  
Heterocyclic Carbenes

Biocatalytic Synthesis of Chiral Amines Using Oxidoreductases

2021 ◽  
pp. 243-283
Author(s):  
Sebastian C. Cosgrove ◽  
Jeremy I. Ramsden ◽  
Juan Mangas‐Sanchez ◽  
Nicholas J. Turner
Keyword(s):  
Chiral Amines
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