Study On The Regioselectivity Addition Reaction Of Conjugate ?-Cyano Alkenylnitrile Compounds With Terminal Enones

The formation of carbon-carbon bond plays an important role in organic synthetic methodology. It lies the foundation of the organic chemistry. Meanwhile, it helps us to find a way to construct a new reaction system and synthesize various functionalized molecules. By far, the Michael addition reaction is one of the most widely used way to construct carbon-carbon bond, and it has an important position in the organic synthesis. In this thesis, it emphasized on the reaction characteristic of the conjugated dienes compounds 2-cyano alkenylnitrile(2), which got from the cyclic ?-halo-enals and malononitrile via the Knoevenagel condensation reaction. To date, some good results have been achieved, and the major study works are summarized as the following several aspects:(1) Making use of cyclic ?-halo-enal with malononitrile as the simply available raw material, the compounds 2-cyano alkenylnitrile(2) were obtained successfully in high yields(up to 80%) which catalysed by methanesulfonic acid/morpholine system. To study the reaction characteristic of 2-cyano alkenylnitrile, some derivatization reactions were carried out in different reaction conditions, then we got a series of derivatives in moderate yield.(2) Compared to the two different synthesis methods of terminal enones, the two-step total synthesis method to get the target products was selected. The reaction was initiated by Friedel-Crafts acylation of aromatic compounds giving the intermediate products, then proceeded through the elimination reaction under the potassium hydroxide giving the terminal enones in moderate yield(up to 72%).(3) Michael addition reaction catalyzed by the base between ?-cyano alkenylnitrile and terminal enones has been developed at room temperature. In consideration of the factors, using readily available, environmentally friendly and cheap materials to get the best yield, the optimal reaction condition was screened using the model reaction of 2-((2-chlorocyclohex-1-enyl)methylene)malononitrile(2a) with 1-phenylprop-2-en-1-one(5a). It turned out that the reaction system is easy of handling under mild reaction conditions(catalyzed by triethylamine in CH2Cl2), and the products can be separated simply. 24 examples were obtained under the optimal reaction condition by the universality of different substrates, and we find that the six-member ring compounds have the best reactivity than other compounds with the yield up to 83%. At the same time, this reaction has a high regioselectivity which can form a quaternary carbon center with the cyano through Michael addition reaction.