scholarly journals Three-component reactions of aromatic amines, 1,3-dicarbonyl compounds, and α-bromoacetaldehyde acetal to access N-(hetero)aryl-4,5-unsubstituted pyrroles

2020 ◽  
Vol 16 ◽  
pp. 2920-2928
Author(s):  
Wenbo Huang ◽  
Kaimei Wang ◽  
Ping Liu ◽  
Minghao Li ◽  
Shaoyong Ke ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Aromatic Amines ◽  
Acid Catalyst ◽  
Pyridine Derivative ◽  
Wide Scope ◽  
Dicarbonyl Compounds ◽  
Lewis Acid Catalyst

N-(Hetero)aryl-4,5-unsubstituted pyrroles were synthesized from (hetero)arylamines, 1,3-dicarbonyl compounds, and α-bromoacetaldehyde acetal by using aluminum(III) chloride as a Lewis acid catalyst through [1 + 2 + 2] annulation. This new versatile methodology provides a wide scope for the synthesis of different functional N-(hetero)aryl-4,5-unsubstituted pyrrole scaffolds, which can be further derived to access multisubstituted pyrrole-3-carboxamides. In the presence of 1.2 equiv of KI, a polysubstituted pyrazolo[3,4-b]pyridine derivative was also successfully synthesized.

scholarly journals Three-Component Reactions of Aromatic Amines, 1,3-Dicarbonyl Compounds and α-Bromoacetaldehyde Acetal to Access N-Aryl/HetAryl-4,5-Unsubstituted Pyrroles

2020 ◽  
Author(s):  
Wenbo Huang ◽  
Kaimei Wang ◽  
Ping Liu ◽  
Shaoyong Ke ◽  
Yanlong Gu
Keyword(s):  
Lewis Acid ◽  
Aromatic Amines ◽  
Acid Catalyst ◽  
Pyridine Derivative ◽  
Wide Scope ◽  
Dicarbonyl Compounds ◽  
Lewis Acid Catalyst

N-Aryl/HetAryl-4,5-unsubstituted pyrroles were synthesized from Ar/HetAr-amines, 1,3-dicarbonyl compounds and α-bromoacetaldehyde acetal by using aluminum(III) chloride as a Lewis acid catalyst through [1 + 2 + 2] annulation. This new versatile methodology provides a wide scope for the synthesis of different functional N-Aryl/HetAryl-4,5-unsubstituted pyrrole scaffolds, which can be further derived to access multi-substituted pyrrole-3-carboxamides. In the presence of 1.2 equiv. of KI, polysubstituted pyrazolo[3,4-b]pyridine derivative was also successfully synthesized.

scholarly journals Anhydrous Titanium(III) chloride as a New Lewis-Acid Catalyst for Ring Opening of Epoxides with Aromatic Amines

2007 ◽  
Vol 2 (2) ◽  
pp. 1934578X0700200
Author(s):  
Suchitra Bhatt ◽  
Sandip K. Nayak
Keyword(s):  
Ambient Temperature ◽  
Lewis Acid ◽  
Aromatic Amines ◽  
Ring Opening ◽  
Acid Catalyst ◽  
Amino Alcohols ◽  
Azide Ion ◽  
Ring Opening Of Epoxides ◽  
Lewis Acid Catalyst

Anhydrous titanium(III) chloride was found to be a simple and efficient Lewis acid catalyst for ring opening of epoxides at ambient temperature. The reaction proceeded smoothly with anilines as well as azide ion as nucleophiles to give the corresponding β-amino alcohols and β-azido alcohols in moderate to good yields.

Ca(CF3COO)2: An efficient Lewis acid catalyst for chemo- and regio-selective enamination of β-dicarbonyl compounds

2010 ◽  
Vol 11 (5) ◽  
pp. 442-446 ◽  
Author(s):  
Mohamed Anoir Harrad ◽  
Rachid Outtouch ◽  
Mustapha Ait Ali ◽  
Larbi El Firdoussi ◽  
Abdallah Karim ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Acid Catalyst ◽  
Dicarbonyl Compounds ◽  
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

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
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