Nitriliminlerin çeşitli dipolarsevenlerle 1,3-dipolar halka katılmalarından potansiyel biyoaktif heterohalkalı bileşiklerin sentezi

1,3-Dipolar cycloadditive methodology occupies a prominent place due to its versatility in the construction of complex heterocylic systems. Pyrazole and pyrazoline containing heterocycles have been intensively synthesized for many years by the nitrilimine cycloaddition reactions with dipolarophilic compounds since the pyrazole or pyrazoline rings are the core structure of many natural products and drugs. For this reason, this Ph.D. dissertation study comprises the synthesis of potential bioactive pyrazoline derivatives by means of nitrilimine cyloaddition reactions. The outcomes of nitrilimine cyloaddition reactions were discussed in five parts;In the first part, as the precursors of nitrilimines, wide range of aryl aldehyde hydrazones and hydrazonyl chlorides were efficiently prepared according to the modified literature methods and characterized.The second part of the work was involved in the synthesis of novel biscycloadducts, namely, aryl substituted dihydro bispyrrolo[3,4-c]pyrazole-4,6-diones, by the reaction of C,N-diarylnitrilimines with bismaleimide derivatives in excellent yields. It should be noted herein that the reaction was absolutely stereoselective and no other regioisomeric product was observed.In the third part, the effect of the substituent groups on para positions of phenyl ring attached to azomethine carbon of biscycloadducts to the absorption maxima values of UV-VIS spectra was investigated by measuring their ultraviolet absorption spectra and by the correlating them with Hammett sigma para constants. Some significant correlation results have been obtained.Fourth part covers the synthesis of novel dihydropyrrolo[3,4-c] pyrazole-4,5-diones by nitrilimine cycloaddition reactions with chiral (R)-N-(1-phenylethyl)maleimide. Regiocontrolled cycloaddition reactions gave rise to formation of either single regioisomer or mixture of regioisomers in some cases.Last part of the thesis was devoted to the investigation of reactivity of nitrilimines with 2-methyl-2-vinyloxirane since there is no reported cycloaddition reaction of nitrilimines to the alkenes bearing epoxide moiety as far as we searched the literature. The reaction took place in regioselective manner and the formation of two diastereomers resulted in each reaction which differs only by the rotation of single bond between oxirane and pyrazoline ring, thus, novel 2-methyl-2-oxiranyl substituted dihydropyrazoles were obtained in low diastereoselectivity.