Phosphorus Lewis acids: emerging reactivity and applications in catalysis

2016 ◽  
Vol 45 (4) ◽  
pp. 765-774 ◽  
Author(s):  
J. M. Bayne ◽  
D. W. Stephan
Keyword(s):  
Lewis Acids ◽  
Main Group ◽  
Focus Attention ◽  
Main Group Chemistry

Part of the renaissance in main group chemistry has been a result of the focus on reactivity and catalysis. In this tutorial review, we focus attention on the role of phosphorus-based Lewis acids in such advances.

scholarly journals Push and pull: the potential role of boron in N2 activation

2018 ◽  
Vol 47 (31) ◽  
pp. 10377-10381 ◽  
Author(s):  
Adam J. Ruddy ◽  
Darren M. C. Ould ◽  
Paul D. Newman ◽  
Rebecca L. Melen
Keyword(s):  
Potential Role ◽  
Main Group ◽  
Main Group Chemistry ◽  
Recent Developments ◽  
Push And Pull ◽  
N2 Activation

Recent developments in main group chemistry towards the activation and conversion of N2 have lead to the revelation that boron can greatly affect these processes.

scholarly journals Theoretical Insight into the Reversal of Chemoselectivity in Diels-Alder Reactions of α,β-Unsaturated Aldehydes and Ketones Catalyzed by Brønsted and Lewis Acids

Organics ◽  
2021 ◽  
Vol 2 (1) ◽  
pp. 38-49
Author(s):  
Lakhdar Benhamed ◽  
Sidi Mohamed Mekelleche ◽  
Wafaa Benchouk
Keyword(s):  
Lewis Acids ◽  
Major Product ◽  
Diels Alder ◽  
Unsaturated Ketone ◽  
Unsaturated Aldehydes ◽  
Aldehydes And Ketones ◽  
Theoretical Insight ◽  
Insight Into ◽  
Good Agreement

Experimentally, a reversal of chemoselectivity has been observed in catalyzed Diels–Alder reactions of α,β-unsaturated aldehydes (e.g., (2E)-but-2-enal) and ketones (e.g., 2-hexen-4-one) with cyclopentadiene. Indeed, using the triflimidic Brønsted acid Tf2NH as catalyst, the reaction gave a Diels–Alder adduct derived from α,β-unsaturated ketone as a major product. On the other hand, the use of tris(pentafluorophenyl)borane B(C6F5)3 bulky Lewis acid as catalyst gave mainly the cycloadduct of α,β-unsaturated aldehyde as a major product. Our aim in the present work is to put in evidence the role of the catalyst in the reversal of the chemoselectivity of the catalyzed Diels–Alder reactions of (2E)-but-2-enal and 2-Hexen-4-one with cyclopentadiene. The calculations were performed at the ωB97XD/6-311G(d,p) level of theory and the solvent effects of dichloromethane were taken into account using the PCM solvation model. The obtained results are in good agreement with experimental outcomes.

scholarly journals On the Coordination Role of Pyridyl-Nitrogen in the Structural Chemistry of Pyridyl-Substituted Dithiocarbamate Ligands

Crystals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 286
Author(s):  
Edward R.T. Tiekink
Keyword(s):  
Transition Metal ◽  
Main Group ◽  
Group Element ◽  
Systematic Research ◽  
Pyridyl Nitrogen ◽  
General Observation ◽  
Supramolecular Architectures ◽  
Main Group Element ◽  
Metal Dithiocarbamates

A search of the Cambridge Structural Database was conducted for pyridyl-substituted dithiocarbamate ligands. This entailed molecules containing both an NCS2− residue and pyridyl group(s), in order to study their complexation behavior in their transition metal and main group element crystals, i.e., d- and p-block elements. In all, 73 different structures were identified with 30 distinct dithiocarbamate ligands. As a general observation, the structures of the transition metal dithiocarbamates resembled those of their non-pyridyl derivatives, there being no role for the pyridyl-nitrogen atom in coordination. While the same is true for many main group element dithiocarbamates, a far greater role for coordination of the pyridyl-nitrogen atoms was evident, in particular, for the heavier elements. The participation of pyridyl-nitrogen in coordination often leads to the formation of dimeric aggregates but also one-dimensional chains and two-dimensional arrays. Capricious behaviour in closely related species that adopted very different architectures is noted. Sometimes different molecules comprising the asymmetric-unit of a crystal behave differently. The foregoing suggests this to be an area in early development and is a fertile avenue for systematic research for probing further crystallization outcomes and for the rational generation of supramolecular architectures.

The role of Lewis acids in promoting the electrocatalytic four-electron reduction of dioxygen

1987 ◽  
pp. 1537 ◽  
Author(s):  
James P. Collman ◽  
Neil H. Hendricks ◽  
Kimoon Kim ◽  
C. Susana Bencosme
Keyword(s):  
Lewis Acids ◽  
Electron Reduction
Sign in / Sign up

Export Citation Format

Share Document