Organic Chemistry

Catalytic Enantioselective Nucleophilic Desymmetrisation of Phosphonate Esters

Authors

Abstract

Compounds containing one or more stereogenic phosphorous atoms in the P(V) oxidation state are important to chemistry, biology and medicine. These include marketed antiviral drugs such as Tenofovir alafenamide and Remdesivir, an effective treatment for Ebola which has also recently been approved for use against SARS-CoV-2 in the US. Existing approaches for the stereoselective synthesis of P-stereogenic centers, while elegant, remain mostly diastereoselective, with catalytic enantioselective approaches remaining limited in application. Accordingly, conceptually novel, broad-scope, catalytic strategies for the efficient stereoselective synthesis of diverse stereogenic P(V) containing compounds remain essential. To this end, we describe a novel enantioselective two-stage strategy, exploiting the first catalytic and highly enantioselective desymmetrisation of phosphonate esters. Pivoting on the stereocontrolled, sequential nucleophilic substitution of enantiotopic leaving groups from readily accessible pro-chiral P(V) precursors, a bifunctional iminophosphorane (BIMP) superbase catalyst was found to be essential in delivering reactive desymmetrised intermediates capable of downstream enantiospecific substitution. This uniquely modular, catalytic platform allows broad-scope, stereoselective access to a diverse library of chiral P(V) compounds including those with O, N and S-linkages.

Content

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Supplementary material

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Supporting Information
Supporting Information including analytical data, NMR spectra and HPLC traces
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Crystallographic Data
Crystallographic Data CIF file
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