A solvent effect on the conformation of aromatic nitro groups

1967 ◽  
Vol 20 (11) ◽  
pp. 2381 ◽  
Author(s):  
ID Rae

The differences between proton mangetic resonance spectra of aromatic nitro compounds in deuterochloroform and dimethyl sulphoxide solutions are interpreted in terms of increased steric requirements of the nitro group in the latter solvent. In suitably ortho-substituted aromatic nitro compounds this leads to twisting of the nitro group about the Ar- N bond.

Synthesis ◽  
2020 ◽  
Vol 53 (01) ◽  
pp. 175-181
Author(s):  
Mieczysław Mąkosza ◽  
Małgorzata Bechcicka ◽  
Krzysztof Wojciechowski

Acetals of dimethyl phenyl- and heteroaryl-α-hydroxymethanephosphonates were deprotonated to generate carbanions, which enter the vicarious nucleophilic substitution (VNS) of hydrogen in aromatic nitro compounds to form 4-nitrobenzhydrylphosphonates and α-heteroaryl-4-nitrobenzylphosphonates. Similarly acetals of cyano­hydrins of heteroaromatic aldehydes (furfural and 2-formylthiophene) react to form heteroaryl 4-nitroarylacetonitriles. The anion of the hemiacetal of acetaldehyde is an efficient leaving group in the base-induced β-elimination step – the crucial step in the VNS reaction. The reaction selectively occurred at the para-position to the nitro group.


1954 ◽  
Vol 26 (7) ◽  
pp. 1238-1240 ◽  
Author(s):  
Enno. Wolthuis ◽  
Stephen. Kolk ◽  
Luke. Schaap

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