scholarly journals Development of a New Heterogeneous Lewis Acid Catalyst for Chemoselective Tetrahydropyranylation of Different Hydroxyl Compounds

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Majid Kolahdoozan ◽  
Mahshid Hossaini
Keyword(s):  
Silica Gel ◽  
Lewis Acid ◽  
Aluminum Chloride ◽  
Acid Catalyst ◽  
Significant Loss ◽  
Heterogeneous Surface ◽  
Effective Catalyst ◽  
Triazine Derivative ◽  
Lewis Acid Catalyst ◽  
Hydroxyl Compounds

Amino functionalized triazine supported on silica-gel was prepared and characterized. This new triazine derivative was applied as a coordinating agent for aluminum chloride. This novel Lewis acid supported on heterogeneous surface was used as an effective catalyst for protection of alcohols and phenols in the presence of 3,4-dihydro-2H-pyran. This catalyst can be reused without any significant loss of activity, and it protects alcohols in the presence of phenols.

scholarly journals Synthesis of Heterogeneous Copper Catalyst Based on Amino-Functionalized Triazine Rings Supported by Silica-Gel for Oxidation of Alcohols

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Majid Kolahdoozan ◽  
Roozbeh Javad Kalbasi ◽  
Mahshid Hossaini
Keyword(s):  
Transition Metal ◽  
Atomic Absorption ◽  
Silica Gel ◽  
Copper Catalyst ◽  
Significant Loss ◽  
Heterogeneous Surface ◽  
Benzylic Alcohols ◽  
Effective Catalyst ◽  
Oxidation Of Alcohols

Amino-functionalized triazine supported on silica-gel was prepared. This new triazine derivate was applied as a coordinating agent for copper (II) and was characterized by different methods. The copper (II) content of the material was determined by atomic absorption. This novel transition metal supported on heterogeneous surface was used as an effective catalyst for oxidation of benzylic alcohols in the presence of H2O2. This catalyst can be reused without any significant loss of activity.

Synthesis of benzophenones using silica-gel supported Lewis acid catalyst

1997 ◽  
Vol 38 (9) ◽  
pp. 1641-1642 ◽  
Author(s):  
Bhushan M. Khadilkar ◽  
Shobha D. Borkar
Keyword(s):  
Silica Gel ◽  
Lewis Acid ◽  
Acid Catalyst ◽  
Lewis Acid Catalyst

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
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