The Synthesis Of 1, 2, 3-Triazoles And Carbonylation Coupling Reaction Catalyzed By Pd

This thesis consists of four chapters.The first chapter is to review the synthesis of 1,2,3-triazoles. 1,2,3-Triazoles are attractive constructs, which have be attented widely. Up to now, they have not been isolated from natural products. We summarize methods for synthesis of 1,2,3-triazoles. 1,3-Dipolar cycloaddition of azides to alkynes is the most important one of them, which was first proposed and studied by Rolf Huisgen. Then Sharpless and Fokin et al developed copper(I)-catalyzed cycloaddition reaction for synthesis of 1,2,3-triazoles.In the second chapter, a series of 1,4,5-trisubstituted 1,2,3-triazoles has been prepared simply and conveniently via 1,3-dipolar cycloaddition/coupling reaction of terminal alkynes, phenylboronic acids and sodium azide in 1,4-dioxane-water using CuI/CuSO₄ as catalyst. In this part, a novel method for synthesizing 1,4,5-trisubstituted 1,2,3-triazoles directly from a variety of phenylboronic acids, sodium azide, and some terminal alkynes has been developed. The procedure does not require isolating of the azide intermediates and it shows a series of advantages, for example, it is safe, efficient, convenient and environmentally benign.In the third chapter, some potential agents for Alzheimer's disease (AD) have been designed and synthesized. The neurodegenerative AD has been recognized as one of the most severe conditions affecting the aged and is life-threatening for this group of people. At the cellular, AD is associated mainly with reduced levels of synaptic acetylcholine (ACh) and other related neurotransmitters. Acetylcholinesterase (AChE) is the enzyme involved in the hydrolysis of the neurotransmitter ACh at cholinergic synapses in the central and peripheral nervous systems. So, a palliative treatment of AD is possible by the use of agents that restore the level of ACh. Inhibitors of AChE activity promote an increase in the concentration and the duration of action of the cholinergic transmission through activation of the synaptic nicotinic and muscarinic receptors. In this part, a series of piperazine compounds has been designed and synthesized, and their AChE inhibitory activity is being evaluated.In the fourth chapter, a series of aryl ferrocenyl ketones has been prepared from iodoferrocene, phenylboronic acids and CO via palladium-catalyzed carbonylation coupling in a short time. The typical procedure for preparing aryl ferrocenyl ketones was via Friedel-Crafts acylation of ferrocene, yet it often afforded a mixture of mono- and di-acylated derivatives together with unreacted starting material. The method avoided formation of di-acylated derivatives compared with currently available Friedel-Crafts acylation methodologies.