Síntese de novas azocinas diversamente funcionalizadas

Abstract

This work is divided into four parts. The first part presents the synthesis of chiral azocines (eight-membered nitrogen heterocycles) by a cycloaddition [2 +2] between tetrahydropyridines (THPs) and ethylpropiolate. The chiral THPs were synthesized from chiral pyridinium salts, which were obtained through Zincke reaction. This strategy gave chiral azocines containing a chiral inductor directly linked to the nitrogen atom. These azocine derivatives were converted in their respective iminium salts by treatment with methanesulfonic acid. These salts were usedfor studies of regioselectivity in nucleophilic addition reactions.The second part of this dissertation shows the attempts to optimize the reaction of iminium ions formation of from achiral azocines as well as the use of these compounds to obtain new products. The iminium salts synthesized were treated with different nucleophiles (sodiumazide and sodium phenolate) to produce some new addition products.The third part describes the synthesis of novel achiral azocine triazole derivatives using a "click" reaction between an 6-azide-azocine and commercial or synthetized alkynes. In this part, four new triazole azocine compounds were obtained. Finally, some preliminary results on the effect of obtained azocines as inhibitors of cholinesterases are presented. The azocine derivatives were tested and did not inhibit the acetylcholinesterase enzyme (AChE), known as an important approach to treat patients with Alzheimer´s disease.