Multiple Bonds between Main‐Group Elements and Transition Metals, CLXV. Rhenium(V) Oxo Complexes with Bidentate Schiff Bases: Structures and Catalytic Applications

Reaction of [NBu 4 ][ReOCl 4 ] ( 1 ) with bidentate salicylidene amine ligands (salen = HL) ( 2a‐c ) leads to the formation of monomeric octahedral rhenium (V) compounds of formula [ReOCl (L) 2 ] ( 3a‐c ). Spectroscopic date indicate asymmetric arrangement of the ligands in the complexes. This is confirmed by the X‐ray crystal structures of 3b and 3c . Complexes 3a, b have been tested as catalysts for the epoxidation of cyclooctene. No evidence for decomposition for decomposition of the catalysts is observed during the reaction (as in the case for tri‐and tetra‐dentate salen complexes). No undesired byproducts are formed in the catalytic reactions.