Thermal factors of protein atoms as determined by X-ray crystallographic techniques show a tendency to be larger in side chains with unfavourable local conformations rather than in those displaying conformational energy minima. It follows that side chain atoms are more mobile if they are in a non-rotameric configuration and that the stereochemistry of protein structures cannot be fully assessed...

Retention of known geometry, with regard to mean atomic positions, has proved useful in the refinement of macromolecules. In structures with a paucity of diffraction data and large displacements of the atoms from their mean positions, it is also of value to restrain the thermal factors to be consistent with known stereochemistry. This paper presents a technique for accomplishing this by restrai...

Unexpected losses in stereochemistry from Stille reactions involving Z-alkenyl halides have been shown to be ligand dependent. A new set of reaction conditions has been developed that, in most cases, leads to highly stereoselective cross-couplings under mild conditions, along with improved yields.