Constitutive activity of ionotropic glutamate receptors via hydrophobic substitutions in the ligand-binding domain.

Neurotransmitter ligands electrically excite neurons by activating ionotropic glutamate receptor (iGluR) ion channels. Knowledge of the iGluR amino acid residues that dominate ligand-induced activation would enable the prediction of function from sequence. We therefore explored the molecular determinants of activity in rat N-methyl-D-aspartate (NMDA)-type iGluRs (NMDA receptors), complex heteromeric iGluRs comprising two glycine-binding GluN1 and two glutamate-binding GluN2 subunits, using amino acid sequence analysis, mutagenesis, and electrophysiology. We find that a broadly conserved aspartate residue controls both ligand potency and channel activity, to the extent that certain substitutions at this position bypass the need for ligand binding in GluN1 subunits, generating NMDA receptors activated solely by glutamate. Furthermore, we identify a homomeric iGluR from the placozoan Trichoplax adhaerens that has utilized native mutations of this crucial residue to evolve into a leak channel that is inhibited by neurotransmitter binding, pointing to a dominant role of this residue throughout the iGluR superfamily.

One-pot borylation/Suzuki-Miyaura sp2-sp3 cross-coupling.

We describe the first one-pot borylation/Suzuki-Miyaura sp2-sp3 cross-coupling between readily available aryl (pseudo)halides and activated alkyl chlorides. This method streamlines the synthesis of diaryl methanes, α-aryl carbonyls and allyl aryl compounds, substructures that are commonly found in life changing drug molecules.

NHC-Cu(I) catalysed asymmetric conjugate silyl transfer to unsaturated lactones: application in kinetic resolution.

The scope of the asymmetric silyl transfer to unsaturated lactones utilising a C2-symmetric NHC-Cu(I) catalyst has been established and kinetic resolutions mediated by silyl transfer have been used to prepare enantiomerically enriched anti-4,5-disubstituted 5-membered lactones. The method has been exploited in an expedient synthesis of (+)-blastmycinone.

SmI2-mediated radical cyclizations directed by a C-Si bond.

The use of a silicon stereocontrol element in cyclobutanol and cyclopentanol-forming cyclizations mediated by SmI(2) results in excellent diastereocontrol. The C-Si bond in the products of cyclization provides a versatile handle for further manipulation. An asymmetric route to cyclization substrates involving copper-catalyzed silyl transfer has also been developed.