The synthesis and investigation of the DNA binding properties of dielectrophiles incorporating bis-vicinal tricarbonyls

Integration of C-Acylation in the Solid-Phase Synthesis of Peptides and Peptidomimetics Employing Meldrum’s Acid, Phosphorus, and Sulfur Ylides

The modification of native peptides to peptidomimetics is an important goal in medicinal chemistry and requires, in many cases, the integration of C-acylation steps involving amino acids with classical peptide synthesis. Many classical C-acylation protocols involving Claisen condensations and the use of ylides are not compatible with peptide synthesis, mostly due to the requirements for strong bases leading to epimerization or deprotection of peptides. Meldrum’s acid as well as several specific phosphorus and sulfur ylides, however, are acidic enough to provide reactive C-nucleophiles under mildly basic conditions tolerated during peptide synthesis. This review provides an overview of peptide-compatible C-acylations using Meldrum’s acid and phosphorus and sulfur ylides, and their application in the medicinal chemistry of peptides.

1 Introduction

2 C-Acylation of Meldrum’s Acid

2.1 C-Acylation of Meldrum’s Acid on Solid Phase

3 Ylides as Substrates for C-Acylation

3.1 C-Acylation of Phosphorus Ylides in Solution Phase

3.2 C-Acylation of Solid-Supported Phosphorus Ylides

3.3 C-Acylation of Sulfur Ylides

3.4 C-Acylation of Solid-Supported Sulfur Ylides

4 Miscellaneous Ylides as Acyl Anion Equivalents

5 Summary

The chemistry of vicinal tricarbonyls and related systems

In this Account, we survey our work on the chemistry of vicinal tricarbonyls and cyano analogues. Methods of preparing the vicinal functionalities are reviewed as well as the use in organic synthesis of these strongly electrophilic aggregates, readily available from carboxylic acids. By attaching neighboring electrophilic groups to the vicinal tricarbonyl, we have developed polyelectrophilic systems, which may be added to di- and trinucleophiles to create novel types of multistep reactivity. Application of tricarbonyl chemistry in synthesis is illustrated by the formation of various natural products or their precursors including fused-ring beta-lactams, indole alkaloids, marine metabolites, enzyme inhibitors containing alpha-keto amides, and bioactive depsipeptides incorporating hydrated tricarbonyl units.

Trioxane dimers have potent antimalarial, antiproliferative and antitumor activities in vitro

A series of tetracyclic and tricyclic trioxane dimers has been prepared with ether and ester tethers of varying length and flexibility. Several of these trioxane dimers have been found to have potent and potentially therapeutically valuable antimalarial, antiproliferative, and antitumor activities in vitro.