Lithium Cobalt-Bis-Dicarbollide: A Novel Lewis Acid Catalyst for the Conjugate Addition of Silyl Ketene Acetals to Hindered .alpha.,.beta.-Unsaturated Carbonyl Compounds

1994 ◽  
Vol 59 (23) ◽  
pp. 6898-6899 ◽  
Author(s):  
William J. DuBay ◽  
Paul A. Grieco ◽  
Lee J. Todd
Keyword(s):  
Lewis Acid ◽  
Carbonyl Compounds ◽  
Acid Catalyst ◽  
Conjugate Addition ◽  
Lewis Acid Catalyst ◽  
Alpha Beta ◽  
Ketene Acetals ◽  
Silyl Ketene Acetals ◽  
Lithium Cobalt

Enantioselective aldol reaction of silyl ketene acetals promoted by a Lewis base-activated Lewis acid catalyst

2009 ◽  
Vol 20 (12) ◽  
pp. 1369-1370 ◽  
Author(s):  
Yasushi Shimoda ◽  
Teppei Tando ◽  
Shunsuke Kotani ◽  
Masaharu Sugiura ◽  
Makoto Nakajima
Keyword(s):  
Lewis Acid ◽  
Aldol Reaction ◽  
Acid Catalyst ◽  
Lewis Base ◽  
Lewis Acid Catalyst ◽  
Ketene Acetals ◽  
Silyl Ketene Acetals

ChemInform Abstract: Enantioselective Aldol Reaction of Silyl Ketene Acetals Promoted by a Lewis Base-Activated Lewis Acid Catalyst.

ChemInform ◽  
2009 ◽  
Vol 40 (47) ◽  
Author(s):  
Yasushi Shimoda ◽  
Teppei Tando ◽  
Shunsuke Kotani ◽  
Masaharu Sugiura ◽  
Makoto Nakajima
Keyword(s):  
Lewis Acid ◽  
Aldol Reaction ◽  
Acid Catalyst ◽  
Lewis Base ◽  
Lewis Acid Catalyst ◽  
Ketene Acetals ◽  
Silyl Ketene Acetals

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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