N-Heterocyclic carbenes for metal-free polymerization catalysis: an update

2015 ◽  
Vol 65 (1) ◽  
pp. 16-27 ◽  
Author(s):  
Stefan Naumann ◽  
Andrew P Dove
Keyword(s):  
Heterocyclic Carbenes ◽  
Metal Free ◽  
Polymerization Catalysis

scholarly journals Recent Advances in Transition-Metal-Free (4+3)-Annulations

Synthesis ◽  
2021 ◽  
Author(s):  
Heather Lam ◽  
Mark Lautens ◽  
Xavier Abel-Snape ◽  
Martin F. Köllen
Keyword(s):  
Transition Metal ◽  
Boronic Acid ◽  
Lewis Acids ◽  
Acid Catalysis ◽  
Heterocyclic Carbenes ◽  
Bronsted Acids ◽  
Metal Free ◽  
Previous Review ◽  
Dual Activation ◽  
Metal Catalyzed

Abstract(4+3)-Annulations are incredibly versatile reactions which combine a 4-atom synthon and a 3-atom synthon to form both 7-membered carbocycles as well as heterocycles. We have previously reviewed transition-metal-catalyzed (4+3)-annulations. In this review, we will cover examples involving bases, NHCs, phosphines, Lewis and Brønsted acids as well as some rare examples of boronic acid catalysis and photocatalysis. In analogy to our previous review, we exclude annulations involving cyclic dienes like furan, pyrrole, cyclohexadiene or cyclopentadiene, as Chiu, Harmata, Fernándes and others have recently published reviews encompassing such substrates. We will however discuss the recent additions (2010–2020) to the literature on (4+3)-annulations involving other types of 4-atom-synthons.1 Introduction2 Bases3 Annulations Using N-Heterocyclic Carbenes3.1 N-Heterocyclic Carbenes (NHCs)3.2 N-Heterocyclic Carbenes and Base Dual-Activation4 Phosphines5 Acids5.1 Lewis Acids5.2 Brønsted Acids6 Boronic Acid Catalysis and Photocatalysis7 Conclusion

scholarly journals Recent Synthesis Developments of Organoboron Compounds via Metal-Free Catalytic Borylation of Alkynes and Alkenes

Molecules ◽  
2018 ◽  
Vol 24 (1) ◽  
pp. 101 ◽  
Author(s):  
Yanmei Wen ◽  
Chunmei Deng ◽  
Jianying Xie ◽  
Xinhuang Kang
Keyword(s):  
Lewis Acids ◽  
Heterocyclic Carbenes ◽  
Lewis Base ◽  
Organoboron Compounds ◽  
Lewis Bases ◽  
Metal Free ◽  
Recent Synthesis

Diboron reagents have been traditionally regarded as “Lewis acids”, which can react with simple Lewis base to create a significant nucleophilic character in one of boryl moieties. In particular, bis(pinacolato)diboron (B2pin2) reacts with simple Lewis bases, such as N-heterocyclic carbenes (NHCs), phosphines and alkoxides. This review focuses on the application of trivalent nucleophilic boryl synthon in the selective preparation of organoboron compounds, mainly through metal-free catalytic diboration and the β-boration reactions of alkynes and alkenes.

Metal free catalytic hydroboration of multiple bonds in methanol using N-heterocyclic carbenes under open atmosphere

2013 ◽  
Vol 11 (37) ◽  
pp. 6350 ◽  
Author(s):  
Kun Wen ◽  
Jinbo Chen ◽  
Feng Gao ◽  
Pinaki S. Bhadury ◽  
Erkang Fan ◽  
...  
Keyword(s):  
Heterocyclic Carbenes ◽  
Multiple Bonds ◽  
Open Atmosphere ◽  
Metal Free

scholarly journals NHC-catalysed highly selective aerobic oxidation of nonactivated aldehydes

2013 ◽  
Vol 9 ◽  
pp. 602-607 ◽  
Author(s):  
Lennart Möhlmann ◽  
Stefan Ludwig ◽  
Siegfried Blechert
Keyword(s):  
Selective Oxidation ◽  
Aerobic Oxidation ◽  
Environmentally Friendly ◽  
Heterocyclic Carbenes ◽  
Metal Free ◽  
Reaction Proceeds ◽  
Selective Aerobic Oxidation ◽  
Terminal Oxidation ◽  
Oxidation Agent

This publication describes a highly selective oxidation of aldehydes to the corresponding acids or esters. The reaction proceeds under metal-free conditions by using N-heterocyclic carbenes as organocatalysts in combination with environmentally friendly oxygen as the terminal oxidation agent.

N-Heterocyclic carbenes (NHCs) as organocatalysts and structural components in metal-free polymer synthesis

2013 ◽  
Vol 42 (5) ◽  
pp. 2142 ◽  
Author(s):  
Maréva Fèvre ◽  
Julien Pinaud ◽  
Yves Gnanou ◽  
Joan Vignolle ◽  
Daniel Taton
Keyword(s):  
Polymer Synthesis ◽  
Heterocyclic Carbenes ◽  
Structural Components ◽  
Metal Free

Heterogeneous catalysts based on built-in N-heterocyclic carbenes with high removability, recoverability and reusability for ring-opening polymerization of cyclic esters

2019 ◽  
Vol 10 (12) ◽  
pp. 1526-1536 ◽  
Author(s):  
Wen Liu ◽  
Guo-Qiang Tian ◽  
Dan-Dan Yang ◽  
Gang Wu ◽  
Si-Chong Chen ◽  
...  
Keyword(s):  
Ring Opening ◽  
Heterogeneous Catalysts ◽  
Ring Opening Polymerization ◽  
Heterocyclic Carbenes ◽  
Catalytic Systems ◽  
Cyclic Esters ◽  
Metal Free ◽  
Critical Issues ◽  
New Generation

Both activity and reusability are critical issues for developing new generation metal-free catalytic systems.

scholarly journals Azaindole synthesis through dual activation catalysis with N-heterocyclic carbenes

2016 ◽  
Vol 52 (59) ◽  
pp. 9283-9286 ◽  
Author(s):  
Hayden A. Sharma ◽  
M. Todd Hovey ◽  
Karl A. Scheidt
Keyword(s):  
Transition Metal ◽  
Heterocyclic Carbenes ◽  
Metal Free ◽  
Dual Activation ◽  
High Yields

A convergent, transition-metal-free synthesis of 2-aryl-azaindoles enabled by carbene catalysis is reported with high yields and a wide substrate scope featuring previously inaccessible azaindoles.

ChemInform Abstract: Metal-Free Arylation of Benzene and Pyridine Promoted by Amino-Linked Nitrogen Heterocyclic Carbenes.

ChemInform ◽  
2012 ◽  
Vol 43 (43) ◽  
pp. no-no
Author(s):  
Wen-Ching Chen ◽  
Yu-Chen Hsu ◽  
Wei-Chun Shih ◽  
Ching-Yu Lee ◽  
Wen-Han Chuang ◽  
...  
Keyword(s):  
Heterocyclic Carbenes ◽  
Metal Free ◽  
Nitrogen Heterocyclic
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