Organic Chemistry: Current Research
Open Access
ISSN: 2161-0401
+44 1478 350008
ISSN: 2161-0401
+44 1478 350008
Basim H Asghar and N El Guesmi
Umm Al-Qura University, Saudi Arabia Faculte des Sciences de Monastir, Tunisia
Posters & Accepted Abstracts: Organic Chem Curr Res
Much interest has been paid to the design of aromatic and hetero aromatic electron-deficient structures exhibiting a high reactivity in nucleophilic aromatic substitutions and related σ-complex formation processes. Annelation of a nitro-substituted phenyl ring by intrinsically electron-withdrawing five-membered rings such as a furoxan ring has proved to be a nice entry to a variety of electron-deficient hetero aromatic structures which exhibit strong electrophilic behavior. Currently, there is a considerable interest in the quantitative measurement of nucleophilic and electrophilic reactivities, particularly in carbon-carbon and carbon-nitrogen bond forming reactions. Mayr and coworkers have used the reactions involving a series of benzhydryl cations to assess the nucleophilicities of carbanions stabilized by acyl, ester, cyano, and nitro groups. The ability to carry out the reactions has led to the conclusion that 4,6-dinitrobenzofuroxan (DNBF) can be a suitable probe to assess the reactivity of weakly nucleophilic carbon or nitrogen centers in general. In this work we present the quantitative assessment of the nucleophilic character of hetero aromatic amines through a kinetic study on the reactions of DNBF with five heterocyclic amines: 2-aminothiazole 2a, 2-aminobenzothiazole 2b, 2-amino-5-trifluoromethyl-1, 3, 4-thiadiazole 2c, 5-amino-3, 4-dimethylisoxazole 2d, and 2-aminopyrimidine 2e.
Recent Publications
1. Terrier, F. Modern Nucleophilic Aromatic Substitution, Wiley-VCH, New York, NY, 2013.
2. Buncel, E. Dust, J. M. Terrier, F. Chem. Rev. 1995, 95, 2261–2280.
3. Asghar, B.H.M. Crampton, M.R. Org. Biomol. Chem. 2007, 5, 1646-1654.
4. Asghar, B.H.M. Crampton, M.R. J. Phys. Org. Chem. 2007, 20, 702-709.
5. Mayr, H. Patz, M. Angew. Chem. Int. Ed. 1994, 33, 938–957.
6. Mayr, H. Kempf, B. Ofial, A.R. Acc. Chem. Res. 2003, 36, 66–77.
Basim H Asghar has completed her Bsc in Chemistry at Umm Al-Qura Uinversity Makkah, Saudi Arabia in 2000 and PhD in Physical Organic Chemistry at Durham University, UK in 2006. Currently, he is a Professor of Physical Organic Chemistry. His research interests focus on kinetic and mechanistic studies of reactions in solution. Thus, in addition to conventional UV/visible spectrophotometers. The work also involves some organic synthesis and the use of NMR spectroscopy. He has published more than 40 research articles in international indexed and refereed journals.