Stille reactions fused heterocycles

Cycloaddition reactions of furans are still widely used as key steps in the construction of complex molecules including natural products. As an example, the intramolecular Diels-Alder cycloaddition of 2-amido substituted furans provides a useful tool for the synthesis of fused, nitrogen-containing poly-heterocycles. Thus, thermolysis of 3-substituted amidofuran produces tricyclic indolinone 39 as a 2 1 mixture of diastereomers via amidofuran cycloaddition-rearrangement methodology, which serves as a key intermediate in the total synthesis of ( )-dendrobine, a major component of the Chinese ornamental orchid Dendrobium nobile . 

In this book, attempts have been made to fuse the two fields heterocyclic chemistry and drug discovery. I hope it will give our undergraduate and graduate students a jump-start in this competitive employment market. As a matter of fact, there is no sacrificing of a solid education in authentic heterocyclic chemistry here. All aspects of reactions, reactivity, and mechanisms are still intact, except they are discussed in the context of medicinal chemistry and drug discovery. 

The development of simple, convenient, and an eco-friendly approach for the S3mthesis of these biologically imporiant compoimds is still in demand. For example, the very useful and green concept of a "click" reaction is a facile, selective, high-peld reaction imder mild water-tolerant conditions with little or no by-products [8]. Cascade armulation reactions lead also to the formation of polycydic fused six- and seven-membered heterocycles with indole and indolizine core [9]. 

The same sequence of reactions, which are carried out intramolecularly, can lead to the new fused polycyclic and macrocyclic pyrrole systems. However, these opportunities arising from the synthesis of N-vinylpyrrole dimers [7,18,701-708] have not been realized still. Here, there is a plenty of room for research creativity of experts in the field of heterocyclic compounds synthesis and polymerization. 

Coffin et al. (2009) have shown the importance of the Stille cross-coupling reaction for the generation of conjugated polymers having fused aromatic heterocycles, especially thiophenes in their backbone. 

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