Current Topics in Medicinal Chemistry - Volume 5, Issue 15, 2005

In the last decades, among the many types of transition-metal catalyzed carbon-carbon bond forming processes, the palladium-catalyzed cross-coupling reactions and the olefin-metathesis reactions have probably played major roles in organic synthesis. Olefin metathesis is now widely considered as one of the most powerful synthetic tools. This reaction, where the carbon-carbon double bond of an alkene is broken and Read More

General considerations on the metathesis reaction are reported and illustrated by examples in the area of natural products and/or biologically active compounds.

With the commercial availability of well-defined ruthenium metathesis catalysts which combine high stability and broad functional group compatibility with undiminished activity, ring-closing metathesis (RCM) is now routinely integrated in the planning of natural product syntheses. Thus, ring sizes of practically any kind from five onward may be formed. The presence of heteroatoms such as oxygen and nitrogen is o Read More

Recent developments of the metathesis reaction in the area of biologically active molecules are presented. Scope and limitations of ring-closing metathesis to form medium and large rings are discussed and illustrated by the epothilone synthesis. Applications of the metathesis reaction related to medicinal chemistry, including solid phase synthesis and combinatorial chemistry are presented.

Olefin metathesis has rapidly established itself as an essential tool in the synthetic chemist's armoury. The ease of operation and functional group tolerance that is obtained with the modern generation of catalysts makes the use of metathesis an extremely attractive option when preparing medicinally interesting molecules. This article will outline some of the ways in which chemists from both industry and academia have be Read More

The success of the early nucleoside agents, the toxicity and metabolic instability of many nucleoside analogues and the effects of viral pathogens on public health are driving the design, synthesis and evaluation of new nucleoside analogues. In this context, a powerful reaction has emerged over the past decade that has fundamentally changed the outlook on nucleoside chemistry: the olefin metathesis reaction. This review is Read More

An overview of the use of olefin cross-metathesis in the synthesis of biologically active natural products is presented. The diverse examples are organized according to the outcome of the olefin constructed by the cross-metathesis reaction: this olefin can be either present in the final product, reduced, engaged in other transformations, or involved in tandem processes.

A summary of the application of ruthenium catalyzed olefin cross-metathesis towards the synthesis of tocopherols (vitamin E) is given. This group of biologically important fat-soluble antioxidants is synthetically available by various routes, for which key-intermediates containing trialkyl-substituted olefinic double bonds can now be prepared efficiently. The results presented may be of interest for the area of syntheses of i Read More