scholarly journals Sydnone anions and abnormal N-heterocyclic carbenes of O-ethylsydnones. Characterizations, calculations and catalyses

2014 ◽  
Vol 50 (80) ◽  
pp. 11822-11824 ◽  
Author(s):  
Sascha Wiechmann ◽  
Tyll Freese ◽  
Martin H. H. Drafz ◽  
Eike G. Hübner ◽  
Jan C. Namyslo ◽  
...  
Keyword(s):  
Heterocyclic Carbenes ◽  
Catalytically Active ◽  
Pd Complexes

Sydnone anions and their deprotonated O-ethyl derivatives (aNHCs) form catalytically active Pd complexes.

ChemInform Abstract: Functionalization of Silicon Surfaces with Catalytically Active Pd Complexes and Application to the Aerobic Oxidation of Benzylic Alcohols.

ChemInform ◽  
2008 ◽  
Vol 39 (9) ◽  
Author(s):  
Kenji Hara ◽  
Shinobu Tayama ◽  
Hidekazu Kano ◽  
Takuya Masuda ◽  
Satoru Takakusagi ◽  
...  
Keyword(s):  
Aerobic Oxidation ◽  
Silicon Surfaces ◽  
Benzylic Alcohols ◽  
Catalytically Active ◽  
Pd Complexes

scholarly journals Modulating NHC catalysis with fluorine

2013 ◽  
Vol 9 ◽  
pp. 2812-2820 ◽  
Author(s):  
Yannick P Rey ◽  
Ryan Gilmour
Keyword(s):  
Small Molecule ◽  
Heterocyclic Carbenes ◽  
Fluorine Substitution ◽  
X Ray ◽  
Catalytically Active ◽  
Triazolium Salts

Fluorination often confers a range of advantages in modulating the conformation and reactivity of small molecule organocatalysts. By strategically introducing fluorine substituents, as part of a β-fluoroamine motif, in a triazolium pre-catalyst, it was possible to modulate the behaviour of the corresponding N-heterocyclic carbene (NHC) with minimal steric alterations to the catalyst core. In this study, the effect of hydrogen to fluorine substitution was evaluated as part of a molecular editing study. X-ray crystallographic analyses of a number of derivatives are presented and the conformations are discussed. Upon deprotonation, the fluorinated triazolium salts generate catalytically active N-heterocyclic carbenes, which can then participate in the enantioselective Steglich rearrangement of oxazolyl carbonates to C-carboxyazlactones (e.r. up to 87.0:13.0).

Functionalization of silicon surfaces with catalytically active Pd complexes and application to the aerobic oxidation of benzylic alcohols

2007 ◽  
pp. 4280 ◽  
Author(s):  
Kenji Hara ◽  
Shinobu Tayama ◽  
Hidekazu Kano ◽  
Takuya Masuda ◽  
Satoru Takakusagi ◽  
...  
Keyword(s):  
Aerobic Oxidation ◽  
Silicon Surfaces ◽  
Benzylic Alcohols ◽  
Catalytically Active ◽  
Pd Complexes

Mono- and dinuclear palladium(ii) complexes containing both N-heterocyclic carbenes and tetrazole ligands as catalysts for Hiyama coupling

2016 ◽  
Vol 40 (11) ◽  
pp. 9739-9745 ◽  
Author(s):  
Jin Yang
Keyword(s):  
Palladium Catalysts ◽  
Coupling Reaction ◽  
Catalytic Performance ◽  
Heterocyclic Carbenes ◽  
Pd Complexes

Six tetrazole ligand stabilized NHC–Pd complexes have been synthesized and fully characterized. Catalytic performance of the obtained palladium catalysts has been investigated for the Hiyama coupling reaction.

Robust and catalytically active mono- and bis-Pd-complexes of the ‘Trost modular ligand’

1999 ◽  
pp. 1707-1708 ◽  
Author(s):  
Craig P. Butts ◽  
John Crosby ◽  
Guy C. Lloyd-Jones ◽  
Susanna C. Stephen
Keyword(s):  
Catalytically Active ◽  
Pd Complexes

Liberation of N-heterocyclic carbenes (NHCs) from thermally labile progenitors: protected NHCs as versatile tools in organo- and polymerization catalysis

2014 ◽  
Vol 4 (8) ◽  
pp. 2466-2479 ◽  
Author(s):  
Stefan Naumann ◽  
Michael R. Buchmeiser
Keyword(s):  
Heterocyclic Carbenes ◽  
Triggered Release ◽  
Polymerization Catalysis ◽  
Catalytically Active ◽  
Thermally Triggered

The thermally triggered release of catalytically active, free NHCs from various heat-sensitive progenitors is discussed.

scholarly journals Activation Mechanism of Nickel(0) N-Heterocyclic Carbene Catalysts Stabilized by Fumarate Ligands

2021 ◽  
Author(s):  
Michael Robo ◽  
Amie Frank ◽  
Ellen Butler ◽  
Alex Nett ◽  
Santiago Canellas ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Ligand Exchange ◽  
Active Species ◽  
Heterocyclic Carbenes ◽  
Activation Mechanism ◽  
Catalyst Stability ◽  
Activation Process ◽  
Catalytic Activities ◽  
Computational Evaluation ◽  
Catalytically Active

Nickel(0) catalysts of N-heterocyclic carbenes (NHCs) that are stabilized by electronic deficient alkenes possess desirable properties of air tolerance and ease of handling while also retaining high catalytic activities. Since catalyst stability often comes at the expense of catalytic activity, we have undertaken a detailed study of the activation mechanism of a new IMes-nickel(0) catalyst stabilized by di-(o-tolyl) fumarate that converts the stable pre-catalyst form into a catalytically active species. Computational evaluation provided evidence against a simple ligand exchange as the activation mechanism, and a stoichiometric activation process that covalently modifies the stabilizing ligand was identified. A detailed computational picture for the activation process was developed, with predictive insights that explain the catalyst features that lead to both active and inactive precatalysts.

Growth of Catalytically Active Nanostructures in the Nonequilibrium Epitaxy Regime

2015 ◽  
Vol 60 (6) ◽  
pp. 546-552
Author(s):  
V.M. Gorshkov ◽  
◽  
V.V. Kuzmenko
Keyword(s):  
Catalytically Active

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.

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