The Coupling-Isomerization Approach to Enimines and the First Sequential Three-Component Access to 2-Ethoxy Pyridines

2004 ◽  
Vol 59 (4) ◽  
pp. 443-450 ◽  
Author(s):  
Oana G. Dediu ◽  
Nasser A. M. Yehia ◽  
Thomas J. J. Müller
Keyword(s):  
Diels Alder ◽  
Isomerization Reaction ◽  
One Pot ◽  
Inverse Electron Demand ◽  
Ketene Acetal ◽  
Electron Demand

AbstractThe coupling-isomerization reaction (CIR) of electron-deficient halides 1 with N-[1-(hetero)arylprop-2-ynyl] tosyl amides 2 leads to the formation of N-tosyl enimines 3, in good to excellent yields. These electron deficient heterodienes are perfectly suited for Diels-Alder reactions with inverse electron demand. In the sense of a one-pot reaction a three-component CIR-cyclocondensation sequence of 1, 2a, and diethyl ketene acetal gives rise to the formation of 2-ethoxy 6-(p-anisyl)pyridines 4 in moderate to good yields.

Tandem inverse electron demand Diels–Alder, retro-Diels–Alder and intramolecular Diels–Alder sequences: one-pot synthesis of diaza-polycycles

Tetrahedron ◽  
2007 ◽  
Vol 63 (26) ◽  
pp. 6004-6014 ◽  
Author(s):  
William J. Bromley ◽  
Mairi Gibson ◽  
Stuart Lang ◽  
Steven A. Raw ◽  
Adrian C. Whitwood ◽  
...  
Keyword(s):  
Diels Alder ◽  
One Pot ◽  
Inverse Electron Demand ◽  
One Pot Synthesis ◽  
Electron Demand

scholarly journals An air-stable bisboron complex: a practical bidentate Lewis acid catalyst

2018 ◽  
Vol 14 ◽  
pp. 618-625 ◽  
Author(s):  
Longcheng Hong ◽  
Sebastian Ahles ◽  
Andreas H Heindl ◽  
Gastelle Tiétcha ◽  
Andrey Petrov ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Acid Catalyst ◽  
Diels Alder ◽  
Organic Transformations ◽  
Nmr Studies ◽  
One Pot ◽  
Efficient Catalyst ◽  
Inverse Electron Demand ◽  
Lewis Acid Catalyst ◽  
Electron Demand

We report an air-stable bisboron complex as an efficient catalyst for the inverse electron-demand Diels–Alder (IEDDA) reaction of 1,2-diazine as well as 1,2,4,5-tetrazine. Its stability towards air and moisture was demonstrated by NMR studies enabling its application in organic transformations without glovebox. A one-pot procedure for its synthesis was developed starting from 1,2-bis(trimethylsilyl)benzene greatly enhancing its practicality. Comparative reactions were carried out to evaluate its catalytic activity in IEDDA reactions of diazine including phthalazine as well as 1,2,4,5-tetrazine.

Tandem Inverse Electron Demand Diels—Alder, Retro-Diels—Alder and Intramolecular Diels—Alder Sequences: One-Pot Synthesis of Diaza-Polycycles.

ChemInform ◽  
2007 ◽  
Vol 38 (42) ◽  
Author(s):  
William J. Bromley ◽  
Mairi Gibson ◽  
Stuart Lang ◽  
Steven A. Raw ◽  
Adrian C. Whitwood ◽  
...  
Keyword(s):  
Diels Alder ◽  
One Pot ◽  
Inverse Electron Demand ◽  
One Pot Synthesis ◽  
Electron Demand

scholarly journals Novel Synthesis of Substituted 2-Trifluoromethyl and 2-Perfluoroalkyl N-Arylpyridinium Compounds—Mechanistic Insights

Molecules ◽  
2019 ◽  
Vol 24 (12) ◽  
pp. 2328 ◽  
Author(s):  
Salem El Kharrat ◽  
Philippe Laurent ◽  
Laurent Boiteau ◽  
Hubert Blancou
Keyword(s):  
Aromatic Amine ◽  
Diels Alder ◽  
One Pot ◽  
Research Directions ◽  
Inverse Electron Demand ◽  
Methoxy Substituent ◽  
New Research ◽  
First Time ◽  
Electron Demand

We report a new one-pot synthesis of 2-trifluoromethylated/2-perfluoroalkylated N-aryl-substituted pyridiniums, 5,6,7,8-tetrahydroquinoliniums and 6,7,8,9-tetrahydro-5H-cyclohepta[b]-pyridinium compounds starting from an activated β-dicarbonyl analogue (here a perfluoro-alkylated gem-iodoacetoxy derivative), an aromatic amine and a (cyclic or acyclic) ketone. The key step of this multicomponent reaction, involves the formation of a 3-perfluoroalkyl-N,N’-diaryl-1,5-diazapentadiene intermediate, various examples of which were isolated and characterized for the first time, together with investigation of their reactivity. We propose a mechanism involving a concurrent inverse electron demand Diels-Alder or Aza-Robinson cascade cyclisation, followed by a bis-de-anilino-elimination. Noteworthy, a meta-methoxy substituent on the aniline directs the reaction towards a 2-perfluoroalkyl-7-methoxyquinoline, resulting from the direct cyclization of the diazapentadiene intermediate, instead of pyridinium formation. This is the first evidence of synthesis of pyridinium derivatives from activated β-dicarbonyls, ketones, and an aromatic amine, the structures of which (both reactants and products) being analogous to species involved in biological systems, especially upon neurodegenerative diseases such as Parkinson’s. Beyond suggesting chemical/biochemical analogies, we thus hope to outline new research directions for understanding the mechanism of in vivo formation of pyridiniums, hence possible pharmaceutical strategies to better monitor, control or prevent it.

scholarly journals Bay-Region-Selective Annulative π-Extension (APEX) of Perylene Diimides with Arynes

Synlett ◽  
2019 ◽  
Vol 30 (04) ◽  
pp. 423-428 ◽  
Author(s):  
Takayuki Nakamuro ◽  
Kazushi Kumazawa ◽  
Hideto Ito ◽  
Kenichiro Itami
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Short Axis ◽  
One Pot ◽  
Perylene Diimides ◽  
Inverse Electron Demand ◽  
Diels Alder Reaction ◽  
Electron Demand

A bay-region-selective annulative π-extension (APEX) reaction of perylene diimides (PDIs) has been achieved by means of in-situ generated reactive aryne intermediates. This method provides an efficient one-pot π-extension at the short axis of PDIs in a sequential manner. Mechanistically, an inverse-electron-demand Diels–Alder reaction might be operative for the transformation.

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