We have screened small molecule libraries specifically for inhibitors that target WWP2, an E3 ubiquitin ligase associated with tumour outgrowth and spread. Selected hits demonstrated dose‐dependent WWP2 inhibition, low micromolar IC50 values, and inhibition of PTEN substrate‐specific ubiquitination. Binding to WWP2 was confirmed by ligand‐based NMR spectroscopy. Furthermore, we used a combination of STD NMR, the recently developed DEEP‐STD NMR approach, and docking calculations, to propose for the first time an NMR‐validated 3D molecular model of a WWP2‐inhibitor complex. These first generation WWP2 inhibitors provide a molecular framework for informing organic synthetic approaches to improve activity and selectivity.
The new asymmetric click CuAAC reaction is used for the first time to induce asymmetry in planar chiral compounds. There are only three classes of stereogenicity (atom‐centred, axial and planar), and these results are therefore of fundamental importance as well as practical significance, providing access to chiral ferrocenes at near enantiopurity. Here, we report asymmetric induction (AI) and kinetic resolution (KR) studies on a novel library of prochiral 1,2,3‐trisubstituted bis‐alkynylferrocenes, obtained by diiodination, derivatisation (including reduction and etherification), double Sonogashira coupling and finally transesterification, azidation or silylation. Desymmetrisation using chiral ligands to modify the CuAAC reaction proceeds in up to 60 % yield and >99.5 % ee, yielding planar chiral ferrocenes. The absolute configuration of two of the preferred products was proved by chemical correlation and related to the entire series by circular dichroism spectroscopy (CD).
1 January 1994 in Journal of the Chemical Society, Chemical Communications
The νCO modes of [(η6-benzocrown ether)Cr(CO)3] complexes in methanol and methanol–water solutions shift to higher wavenumber with addition of alkali metal salts to the solution; this wavenumber shift correlates with the cation concentration such that the complexes can be used as molecular sensors for the metal cations.
The preparation of a series of new prochiral bis-alkynes is reported. A selection of chiral ligands is examined to gain additional information about the scope of the new asymmetric Huisgen ‘click’ reaction [the desymmetrisation of bis-alkynes using chiral ligands in conjunction with the widely applied copper-catalysed azide–alkyne cycloaddition (CuAAC) triazole synthesis]. The development of a new chiral assay for (±)-methyl 2-[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]-2-cyanopent-4-ynoate, and the production of this mono-triazole in up to 18% enantiomeric excess is described.
12 November 2015 in Chemistry – A European Journal