Spatial Recognition Within Terpenes: Redox and H-bond Promoted Linkage Isomerizations and the Selective Binding of Complex Alkenes.

A method for the resolution of η 2-alkene-complex isomers of the type MoTp(NO)(DMAP)(η 2-alkene) and WTp(NO)(PMe3)(η 2-alkene) (where Tp = hydridotris(pyrazolyl)-borate and DMAP = 4-(dimethylamino)pyridine) has been explored. Alkene and polyene compounds form as a mixture of kinetically trapped isomers. For both types of complexes, it was found that addition of either a fluorinated alcohol or one-electron oxidant reduces the number of isomers in solution. Accelerated ligand exchange was also observed, although these reactions were accompanied by significant decomposition.