The Effect of the Leaving Group in N-Heterocyclic Carbene-Catalyzed Nucleophilic Aromatic Substitution Reactions

2020 ◽  
Vol 93 (12) ◽  
pp. 1424-1429
Author(s):  
Kosuke Yasui ◽  
Miharu Kamitani ◽  
Hayato Fujimoto ◽  
Mamoru Tobisu
Keyword(s):  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Substitution Reactions ◽  
Leaving Group

A new leaving group in nucleophilic aromatic substitution reactions (SNAr)

2008 ◽  
Vol 2008 (8) ◽  
pp. 432-433 ◽  
Author(s):  
Mehdi Bakavoli ◽  
Mehdi Pordel ◽  
Mohammad Rahimizadeh ◽  
Pooneh Jahandari
Keyword(s):  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Substitution Reactions ◽  
Leaving Group

scholarly journals The Element Effect Revisited: Factors Determining Leaving Group Ability in Activated Nucleophilic Aromatic Substitution Reactions

2012 ◽  
Vol 77 (21) ◽  
pp. 9535-9540 ◽  
Author(s):  
Nicholas A. Senger ◽  
Bo Bo ◽  
Qian Cheng ◽  
James R. Keeffe ◽  
Scott Gronert ◽  
...  
Keyword(s):  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Substitution Reactions ◽  
Leaving Group ◽  
Leaving Group Ability

scholarly journals Reactivity in the nucleophilic aromatic substitution reactions of pyridinium ions

2014 ◽  
Vol 12 (32) ◽  
pp. 6175-6180 ◽  
Author(s):  
Jeannette T. Bowler ◽  
Freeman M. Wong ◽  
Scott Gronert ◽  
James R. Keeffe ◽  
Weiming Wu
Keyword(s):  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Substitution Reactions ◽  
Leaving Group ◽  
Barrier Free ◽  
Pyridinium Ions

The nucleophilic aromatic substitution reactions of piperidine with N-methylpyridinium ions in methanol occur via rate determining preassociation of a second piperidine molecule with the addition intermediate followed by barrier-free deprotonation. Loss of leaving group is concurrent with deprotonation for Cl, Br, and I (E2), but subsequent to deprotonation, although rapid, for CN and F (E1cBIRR).

scholarly journals The use of bisphthalonitriles in the synthesis of side-strapped 1,11,15,25-tetrasubstituted phthalocyanines

1996 ◽  
Vol 74 (3) ◽  
pp. 307-318 ◽  
Author(s):  
Clifford C. Leznoff ◽  
David M. Drew
Keyword(s):  
Key Words ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Substitution Reactions ◽  
Pure Compounds

Nucleophilic aromatic substitution reactions of 3-nitrophthalonitrile yield 3-hydroxyphthalonitrile and 3-neopentoxyphthalonitrile, the latter of which condensed to 1,8,15,22-tetraneopentoxyphthalocyanine as a mixture of isomers. Bisphthalonitriles such as 1,3-bis(2′,3′-dicyanophenoxy)-2,2-dipentylpropane, 1,3-bis(2′,3′-dicyanophenoxy)-2,2-diethylpropane, 1,3-bis(2′,3′-dicyanophenoxy)-2,2-dioctylpropane, and 1,3-bis(2′,3′-dicyanophenoxy)-2-methyl-2-trityloxymethylpropane all gave bis-crown-like 1,11,15,25-tetrasubstituted phthalocyanines as pure compounds when treated with lithium octoxide in 1-octanol at 196 °C. A host of nine other bisphthalonitriles including 1,5-bis(2′,3′-dicyanophenoxy)-3-oxapentane, 1,1-bis(2′,3′-dicyanophenoxymethyl)cyclohexane, 1,2-bis(2′,3′-dicyanophenoxymethyl)benzene, and 2,5-bis(2′,3′-dicyanophenoxymethyl)furan did not dimerize to mononuclear phthalocynaines. The "gem dimethyl" effect was suggested as a reason for the successful macrocyclizations. Key words: nucleophilic aromatic substitution, phthalonitriles, bisphthalonitriles, 1,11,15,25-tetrasubstituted phthalocyanines.

scholarly journals Synthesis and fluorescent properties of N(9)-alkylated 2-amino-6-triazolylpurines and 7-deazapurines

2019 ◽  
Vol 15 ◽  
pp. 474-489 ◽  
Author(s):  
Andrejs Šišuļins ◽  
Jonas Bucevičius ◽  
Yu-Ting Tseng ◽  
Irina Novosjolova ◽  
Kaspars Traskovskis ◽  
...  
Keyword(s):  
Nucleophilic Aromatic Substitution ◽  
Secondary Amines ◽  
Acetonitrile Solution ◽  
Quantum Yields ◽  
Cell Labelling ◽  
Aromatic Substitution ◽  
Fluorescent Properties ◽  
Substitution Reactions ◽  
Low Cytotoxicity ◽  
Electron Donating Groups

The synthesis of novel fluorescent N(9)-alkylated 2-amino-6-triazolylpurine and 7-deazapurine derivatives is described. A new C(2)-regioselectivity in the nucleophilic aromatic substitution reactions of 9-alkylated-2,6-diazidopurines and 7-deazapurines with secondary amines has been disclosed. The obtained intermediates, 9-alkylated-2-amino-6-azido-(7-deaza)purines, were transformed into the title compounds by CuAAC reaction. The designed compounds belong to the push–pull systems and possess promising fluorescence properties with quantum yields in the range from 28% to 60% in acetonitrile solution. Due to electron-withdrawing properties of purine and 7-deazapurine heterocycles, which were additionally extended by triazole moieties, the compounds with electron-donating groups showed intramolecular charge transfer character (ICT/TICT) of the excited states which was proved by solvatochromic dynamics and supported by DFT calculations. In the 7-deazapurine series this led to increased fluorescence quantum yield (74%) in THF solution. The compounds exhibit low cytotoxicity and as such are useful for the cell labelling studies in the future.

scholarly journals The Truce–Smiles rearrangement and related reactions: a review

2017 ◽  
Vol 95 (5) ◽  
pp. 483-504 ◽  
Author(s):  
Anna R.P. Henderson ◽  
Joel R. Kosowan ◽  
Tabitha E. Wood
Keyword(s):  
Nucleophilic Aromatic Substitution ◽  
Future Research ◽  
Tandem Reaction ◽  
Aromatic Substitution ◽  
Smiles Rearrangement ◽  
Research Directions ◽  
Reaction Method ◽  
Design Variables ◽  
Leaving Group ◽  
Future Research Directions

The Truce–Smiles rearrangement is an X → C aryl migration reaction that is achieved by an intramolecular nucleophilic aromatic substitution pathway. The reaction exhibits a wide substrate scope with respect to a migrating aryl ring and leaving group, appearing in many different tandem reaction sequences, to achieve a wide variety of product outcomes. We present an extensive survey of reported examples of the Truce–Smiles rearrangement from the chemistry literature (1950s until present) organized by various substrate design variables or aspects of the reaction method. Present deficiencies in our understanding of the reaction are identified with recommendations for future research directions and useful developments in the application of the reaction are celebrated.

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