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

A method for the resolution of η2-alkene-complex isomers of the type MoTp­(NO)­(DMAP)­(η2-alkene) and WTp­(NO)­(PMe3)­(η2-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.