Metal-free electrocatalyst for reducing nitrogen to ammonia using a Lewis acid pair

2019 ◽  
Vol 7 (9) ◽  
pp. 4865-4871 ◽  
Author(s):  
Li Shi ◽  
Qiang Li ◽  
Chongyi Ling ◽  
Yehui Zhang ◽  
Yixin Ouyang ◽  
...  
Keyword(s):  
Lewis Acid ◽  
High Efficiency ◽  
Acid Catalyst ◽  
Acid Sites ◽  
Activation Mechanism ◽  
Ambient Conditions ◽  
Lewis Acid Sites ◽  
Metal Free ◽  
Nitrogen Activation ◽  
Lewis Acid Catalyst

Metal-free Lewis acid catalyst is developed as a high-efficiency electrocatalyst to enable nitrogen reduction under ambient conditions. A new nitrogen activation mechanism via the pull–pull effect between Lewis acid sites and nitrogen is also proposed.

Metal-free boron carbonitride with tunable boron Lewis acid sites for enhanced nitrogen electroreduction to ammonia

2021 ◽  
Vol 283 ◽  
pp. 119622
Author(s):  
Bin Chang ◽  
Lili Li ◽  
Dong Shi ◽  
Hehe Jiang ◽  
Zizheng Ai ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Acid Sites ◽  
Lewis Acid Sites ◽  
Boron Carbonitride ◽  
Metal Free

Sulfonated dendritic mesoporous silica nanospheres: a metal-free Lewis acid catalyst for the upgrading of carbohydrates

2020 ◽  
Vol 22 (5) ◽  
pp. 1754-1762 ◽  
Author(s):  
Erlen Y. C. Jorge ◽  
Carolina G. S. Lima ◽  
Thiago M. Lima ◽  
Lucas Marchini ◽  
Manoj B. Gawande ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Lignocellulosic Biomass ◽  
Lewis Acid ◽  
Acid Catalyst ◽  
Viable Alternative ◽  
Fine Chemicals ◽  
Silica Nanospheres ◽  
Metal Free ◽  
Lewis Acid Catalyst ◽  
Mesoporous Silica Nanospheres

Lignocellulosic biomass is becoming a viable alternative or a complementary source for obtaining petroleum-derived products such as fuels, polymers and fine chemicals, among others.

Computationally-Guided Investigation of Dual Amine/pi Lewis Acid Catalysts for Direct Additions of Aldehydes and Ketones to Unactivated Alkenes and Alkynes

2020 ◽  
Author(s):  
Eric Greve ◽  
Jacob D. Porter ◽  
Chris Dockendorff
Keyword(s):  
Lewis Acid ◽  
Density Functional ◽  
Acid Catalyst ◽  
Metal Catalyst ◽  
Catalyst Poisoning ◽  
Lewis Acid Catalysts ◽  
Metal Ligands ◽  
Aldehydes And Ketones ◽  
Lewis Acid Catalyst ◽  
Catalyst Systems

Dual amine/pi Lewis acid catalyst systems have been reported for intramolecular direct additions of aldehydes/ketones to unactivated alkynes and occasionally alkenes, but related intermolecular reactions are rare and not presently of significant synthetic utility, likely due to undesired coordination of enamine intermediates to the metal catalyst. We reasoned that bulky metal ligands and bulky amine catalysts could minimize catalyst poisoning and could facilitate certain examples of direct intermolecular additions of aldehyde/ketones to alkenes/alkynes. Density Functional Theory (DFT) calculations were performed that suggested that PyBOX-Pt(II) catalysts for alkene/alkyne activation could be combined with MacMillan’s imidazolidinone organocatalyst for aldehyde/ketone activation to facilitate desirable C-C bond formations, and certain reactions were calculated to be more exergonic than catalyst poisoning pathways. As calculated, preformed enamines generated from the MacMillan imidazolidinone did not displace ethylene from a biscationic (<i>t</i>-Bu)PyBOX-Pt<sup>2+</sup>complex, but neither were the desired C-C bond formations observed under several different conditions.

Computationally-Guided Investigation of Dual Amine/pi Lewis Acid Catalysts for Direct Additions of Aldehydes and Ketones to Unactivated Alkenes and Alkynes

2020 ◽  
Author(s):  
Eric Greve ◽  
Jacob D. Porter ◽  
Chris Dockendorff
Keyword(s):  
Lewis Acid ◽  
Density Functional ◽  
Acid Catalyst ◽  
Metal Catalyst ◽  
Catalyst Poisoning ◽  
Lewis Acid Catalysts ◽  
Metal Ligands ◽  
Aldehydes And Ketones ◽  
Lewis Acid Catalyst ◽  
Catalyst Systems

Dual amine/pi Lewis acid catalyst systems have been reported for intramolecular direct additions of aldehydes/ketones to unactivated alkynes and occasionally alkenes, but related intermolecular reactions are rare and not presently of significant synthetic utility, likely due to undesired coordination of enamine intermediates to the metal catalyst. We reasoned that bulky metal ligands and bulky amine catalysts could minimize catalyst poisoning and could facilitate certain examples of direct intermolecular additions of aldehyde/ketones to alkenes/alkynes. Density Functional Theory (DFT) calculations were performed that suggested that PyBOX-Pt(II) catalysts for alkene/alkyne activation could be combined with MacMillan’s imidazolidinone organocatalyst for aldehyde/ketone activation to facilitate desirable C-C bond formations, and certain reactions were calculated to be more exergonic than catalyst poisoning pathways. As calculated, preformed enamines generated from the MacMillan imidazolidinone did not displace ethylene from a biscationic (<i>t</i>-Bu)PyBOX-Pt<sup>2+</sup>complex, but neither were the desired C-C bond formations observed under several different conditions.

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