Controlled molecular design of ether- and ester-bridged norbornenes and their ring-opening metathesis polymerizations

1999 ◽  
Vol 77 (11) ◽  
pp. 1797-1809 ◽  
Author(s):  
Alaa S Abd-El-Aziz ◽  
Andrea L Edel ◽  
Leslie J May ◽  
Karen M Epp ◽  
Harold M Hutton
Keyword(s):  
Ring Opening ◽  
Molecular Design ◽  
Polymeric Materials ◽  
Ruthenium Catalysts ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Aryl Ether ◽  
Substitution Reactions ◽  
Nmr Techniques ◽  
Norbornene Derivatives

A series of functionalized polynorbornenes containing pendent ether- or ester-bridged poly(aromatic ether) chains were prepared. The ether-bridged norbornene complex was synthesized via cyclopentadienyliron-mediated nucleophilic aromatic substitution reactions. This methodology, combined with that of dicyclohexylcarbodiimide-mediated coupling, allowed for the formation of novel oligomeric aryl ether and ester substituted norbornene complexes. Photolytic demetallation gave the monomers in good yields. Structural identification of the exo and endo isomers of both the metallated and demetallated norbornene derivatives was accomplished using HH and CH COSY NMR techniques. Ring-opening metathesis polymerization (ROMP) of these monomers using RuCl3(hydrate) and (Cy3P)2Cl2Ru=CHPh allowed for the preparation of the functionalized polynorbornenes. Thermal analysis of the resulting polymeric materials demonstrated greater thermal stability as the number of aryl ether groups increased.Key words: aromatic ethers, cyclopentadienyliron, polynorbornene, ROMP, ruthenium catalysts.

Mechanism of nucleophilic substitution reactions of 4-(4ˊ-nitro)phenylnitrobenzofurazan ether with aniline in acetonitrile.

2017 ◽  
Vol 2 (10) ◽  
Author(s):  
K. Gbayo ◽  
C. Isanbor ◽  
K. Lobb ◽  
O. Oloba-Whenu
Keyword(s):  
Density Functional Theory ◽  
Nuclear Magnetic Resonance ◽  
Density Functional ◽  
Theoretical Study ◽  
Activation Parameters ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Substitution Reactions ◽  
Functional Theory ◽  
Nmr Techniques

Abstract Rate constants and activation parameters obtained for the nucleophilic aromatic substitution reactions (SNAr) of 4-substitutedphenoxy-7-nitrobenzoxadiazole (1) with aniline in acetonitrile at varying temperature using Nuclear Magnetic Resonance (NMR) techniques were reported. These results were compared with the theoretical study which identifies transformations and intermediates using Density Functional Theory (DFT).

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.

Highly photoluminescent poly(norbornene)s carrying platinum-acetylide complex moieties in the side chain: evaluation of oxygen sensing and TTA–UC

2021 ◽  
Author(s):  
Taichi Sotani ◽  
Toshiko Mizokuro ◽  
Tatsuo Yajima ◽  
Hiromitsu Sogawa ◽  
Fumio Sanda
Keyword(s):  
Ring Opening ◽  
Oxygen Sensing ◽  
Polymeric Materials ◽  
Side Chain ◽  
Thermally Stable ◽  
Ring Opening Metathesis Polymerization ◽  
Metathesis Polymerization ◽  
Norbornene Derivatives

Ring-opening metathesis polymerization (ROMP) of norbornene derivatives is useful for preparing thermally stable and transparent polymeric materials with good moldability. This study deals with ROMP of norbornene monomer 1 bearing...

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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