Strong Lewis acidic catalysts for C–F bond activation by fluorination of activated γ-Al2O3

2020 ◽  
Vol 10 (2) ◽  
pp. 391-402
Author(s):  
Clara Patricia Marshall ◽  
Gudrun Scholz ◽  
Thomas Braun ◽  
Erhard Kemnitz
Keyword(s):  
Lewis Acid ◽  
Bond Activation ◽  
Aluminium Oxide ◽  
Acid Catalyst ◽  
Acidic Catalysts ◽  
Lewis Acid Catalyst

A strong solid Lewis acid catalyst has been successfully obtained by modifying a known procedure of fluorinating γ-aluminium oxide, which was pre-calcined under vacuum.

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.

Bis(pentafluorophenyl)tin Dibromide as a Novel Organotin Halide Lewis Acid Catalyst

Synlett ◽  
1996 ◽  
Vol 1996 (09) ◽  
pp. 877-879 ◽  
Author(s):  
Jianxie Chen ◽  
Katsumasa Sakamoto ◽  
Akihiro Orita ◽  
Junzo Otera
Keyword(s):  
Lewis Acid ◽  
Acid Catalyst ◽  
Lewis Acid Catalyst

Asymmetric synthesis of isoquinuclidines by Diels–Alder reaction of 1,2-dihydropyridine utilizing a chiral Lewis acid catalyst

Tetrahedron ◽  
2012 ◽  
Vol 68 (6) ◽  
pp. 1774-1781 ◽  
Author(s):  
Chigusa Seki ◽  
Masafumi Hirama ◽  
N.D.M. Romauli Hutabarat ◽  
Junko Takada ◽  
Chonticha Suttibut ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Lewis Acid ◽  
Acid Catalyst ◽  
Alder Reaction ◽  
Diels Alder ◽  
Diels Alder Reaction ◽  
Chiral Lewis Acid ◽  
Lewis Acid Catalyst

ZrOCl2·8H2O: an efficient Lewis acid catalyst for the one-pot multicomponent synthesis of β-acetamido ketones

Tetrahedron ◽  
2006 ◽  
Vol 62 (17) ◽  
pp. 4059-4064 ◽  
Author(s):  
Rina Ghosh ◽  
Swarupananda Maiti ◽  
Arijit Chakraborty ◽  
Santu Chakraborty ◽  
Alok K. Mukherjee
Keyword(s):  
Lewis Acid ◽  
Acid Catalyst ◽  
Multicomponent Synthesis ◽  
One Pot ◽  
Lewis Acid Catalyst ◽  
The One

On the structural features of the chiral organometallic Lewis-acid catalyst “(dibornacyclopentadienyl)zirconiumtrichloride”

1993 ◽  
Vol 459 (1-2) ◽  
pp. 107-115 ◽  
Author(s):  
Gerhard Erker ◽  
Jutta Schamberger ◽  
Adolphus A.H. van der Zeijden ◽  
Stefan Dehnicke ◽  
Carl Krüger ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Acid Catalyst ◽  
Structural Features ◽  
Lewis Acid Catalyst

Synthesis of Carbamates Using Yttria-Zirconia Based Lewis Acid Catalyst.

ChemInform ◽  
2004 ◽  
Vol 35 (12) ◽  
Author(s):  
Rajesh K. Pandey ◽  
Sharda P. Dagade ◽  
Mohan K. Dongare ◽  
Pradeep Kumar
Keyword(s):  
Lewis Acid ◽  
Acid Catalyst ◽  
Lewis Acid Catalyst
Sign in / Sign up

Export Citation Format

Share Document