C-C and C-N bond formation reactions of cyclic systems

For thousands of years, nature, especially plant life, was the `pharmacy? from which people obtained their medicines. Even today it is estimated that 40 % of all drugs contain at least one plant-derived ingredient.Epibatidine molecule ? exo-2-(6-chloro-3-pyridyl)-7-azabicyclo[2.2.1]heptane ? which was isolated by Daly and coworkers in 1992 from the skin of Ecuadorian frog, Epipedobates tricolor lives in ecvator area, has potential interest among the nicotinic receptor agonists for treating neurological disorders such as alzheimer?s, parkinson?s diseases and schizophrenia [1].Epibatidine?s toxic effects and the fact that the amount of this compound had been isolated from Epipedobates tricolor less than one miligram, causes the need of synthesizing new epibatidine analogs which are not toxic but has the same biological active properties. Therefore this has great importance to synthesize new epiboxidine analogs which less toxic but have the same effect of drug.Furthermore, the arylation and alkenization of alkenes in presence of palladium catalyst in organic synthesis named as Heck reaction, keep their currency as very effective catalyzing method in forming carbon-carbon bonds. Recently, the asymmetric Heck-type hydroarylation of specific bicyclic ring systems of alkenes have been examined intensively, because of the easily obtained stereoselective results [2], 3], [4], [5], [6].On the other hand, dipolar cycloaddition reactions has found many useful synthetic applications, particularly with respect to the preparation of compounds with new chiral centers. Nitrile oxides are versatile intermediates in heterocyclic chemistry, taking part in a variety of 1,3-dipolar cycloadditions to give various five-membered heterocycles. In particular, cycloaddition of nitrile oxides to olefines are of considerable interest as the resulting isoxazolines are pharmacophores of note in several pharmaceutically important compounds [7], [8].This study planned as four steps. The first step is the synthesizing of starting materials N-(3-methylisoxazol-5-yl)bicyclo[2.2.1]hept-8-ene-2-endo,6-endo-dicarboximide and N-(3-methylisoxazol-5-yl)-10-oxabicyclo[2.2.1]hept-8-ene-2-exo,6-exo-dicarboximide. The second step is including hydroarylation reactions of these tricyclic imide derivatives with aryl(hetaryl) iodides. On the third step, we performed 1,3-dipolar cycloaddition reactions of starting materials with nitrile oxides to obtain isoxazoline derivatives. The last step is including structure characterizations of all new compounds by FTIR, 1H NMR, 13C NMR (APT) and GC-MS techniques, respectively.