scholarly journals Icosahedral Meta-Carboranes Containing Exopolyhedral B-Se and B-Te Bonds

2021 ◽  
Author(s):  
Harrison Mills ◽  
Fadi Alsarhan ◽  
Ta-Chung Ong ◽  
Milan Gembicky ◽  
Arnold Rheingold ◽  
...  
Keyword(s):  
Cross Coupling ◽  
Nucleophilic Aromatic Substitution ◽  
Grignard Reagents ◽  
Aromatic Substitution ◽  
Substitution Reactions ◽  
Reactivity Pattern ◽  
Electrophilic Reactions ◽  
Substitution Chemistry ◽  
Electrophilic Reactivity

Chalcogen-containing carboranes have been known for several decades and possess stable exopolyhedral B(9)-Se and B(9)-Te σ bonds despite the electron-donating ability of the B(9) vertex. While these molecules are known, little has been done to thoroughly evaluate their electrophilic and nucleophilic behavior. Herein, we report an assessment of the electrophilic reactivity of meta-carboranyl selenyl (II), tellurenyl (II), and tellurenyl (IV) chlorides and establish their reactivity pattern with Grignard reagents, alkenes, alkynes, enolates, and electron-rich arenes. These electrophilic reactions afford unique electron-rich B-Y-C (Y = Se, Te) bonding motifs not commonly found before. Furthermore, we show that meta-carboranyl selenolate, and even meta-carboranyl tellurolate, can be competent nucleophiles and participate in nucleophilic aromatic substitution reactions. Arene substitution chemistry is shown to be further extended to electron-rich species via the palladium mediated cross-coupling chemistry.

scholarly journals Synthesis and stability of strongly acidic benzamide derivatives

2018 ◽  
Vol 14 ◽  
pp. 523-530 ◽  
Author(s):  
Frederik Diness ◽  
Niels J Bjerrum ◽  
Mikael Begtrup
Keyword(s):  
Organic Acids ◽  
Aqueous Solutions ◽  
Cross Coupling ◽  
Nucleophilic Aromatic Substitution ◽  
Benzoic Acids ◽  
Aromatic Substitution ◽  
Substitution Reactions ◽  
Dilute Aqueous Solutions ◽  
Derivatives Of ◽  
Benzamide Derivatives

Reactivity studies of strong organic acids based on the replacement of one or both of the oxygens in benzoic acids with the trifluoromethanesulfonamide group are reported. Novel derivatives of these types of acids were synthesized in good yields. The generated N-triflylbenzamides were further functionalized through cross-coupling and nucleophilic aromatic substitution reactions. All compounds were stable in dilute aqueous solutions. Studies of stability under acidic and basic conditions are also reported.

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.

Nucleophilic Aromatic Substitution Reactions in Water Enabled by Micellar Catalysis

2015 ◽  
Vol 17 (19) ◽  
pp. 4734-4737 ◽  
Author(s):  
Nicholas A. Isley ◽  
Roscoe T. H. Linstadt ◽  
Sean M. Kelly ◽  
Fabrice Gallou ◽  
Bruce H. Lipshutz
Keyword(s):  
Micellar Catalysis ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Substitution Reactions
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