New rhenium(III) semiclathrochelates with biorelevant apical substituents: Synthesis, X-ray structure and reactivity

One-pot reduction-condensation of K2ReCl6, the corresponding α-dioxime and an appropriate boronic acid in the presence of Ag as reductant gave the mixture the boron-capped rhenium(III) tris-dioximates with their reduced diimine-iminoximate derivatives, resulted from the side domino-reaction. Template condensation of nioxime and 3-formylphenylboronic acid on a rhenium(III) ion afforded a formyl-terminated rhenium(III) tris-nioximate, undergoing a further H+-catalyzed condensation with isoniazid as vector substituent to give the semiclathrochelate hydrazone with apical functionalizing group.177