Synthesis of a C-Nucleoside Phosphonate by Base-Promoted Epimerization

Stereocontrolled Synthesis of Aryl C-Nucleosides under Ambient Conditions

A stereocontrolled synthesis of an aryl C-nucleoside has been developed using D-ribals and arylboronic acids catalyzed by palladium without additional ligands in common solvents under an open-air atmosphere at room temperature. This protocol features very mild conditions, simplicity in operation, exclusive β-stereoselectivity, broad substrate scopes, and good compatibility with reactive amino and hydroxyl groups. The functionalization of unsaturated C-nucleosides and the late-stage glycosylation of natural products/drugs demonstrated the high practicality of this strategy.

Synthesis and evaluation of a collection of purine-like C-nucleosides as antikinetoplastid agents

The kinetoplastid parasites Trypanosoma brucei, Trypanosoma cruzi and Leishmania spp. are the causative agents of neglected tropical diseases with a serious burden in several parts of the world. These parasites are incapable of synthesizing purines de novo, and therefore rely on ingenious purine salvage pathways to acquire and process purines from their host. Purine nucleoside analogs that may interfere with these pathways therefore constitute a privileged source of new antikinetoplastid agents. In this study, we synthetized a collection of C-nucleosides employing five different heterocyclic nucleobase surrogates. C-nucleosides are chemically and enzymatically stable and allow for extensive structural modification. Inspired by earlier 7-deazaadenosine nucleosides and known antileishmanial C-nucleosides, we introduced different modifications tailored towards antikinetoplastid activity. Both adenosine and inosine analogs were synthesized with the aim of discovering new antikinetoplastid hits and expanding knowledge of structure-activity relationships. Several promising hits with potent activity against Trypanosoma brucei, Trypanosoma cruzi and Leishmania infantum were discovered, and the nature of the nucleobase surrogate was found to have a profound influence on the selectivity profile of the compounds.

Enzymatic Transition States and Drug Design

Transition state theory teaches that chemically stable mimics of enzymatic transition states will bind tightly to their cognate enzymes. Kinetic isotope effects combined with computational quantum chemistry provides enzymatic transition state information with sufficient fidelity to design transition state analogues. Examples are selected from various stages of drug development to demonstrate the application of transition state theory, inhibitor design, physicochemical characterization of transition state analogues, and their progress in drug development.