New hydroxylamine-containing macrobicyclic encapsulating ligand: Unexpected double addition of ethyl radicals to the azomethine fragment of a boron-capped iron(II) clathrochelate dioximate

The reaction of the fluoroboron-capped mixed dimethylglyoximate-α-benzyldioximate iron(II) clathrochelate with (C2H5)3B–O2 system as a “soft” radical source afforded the major macrobicyclic product of the reductive addition of two carbon-centered radicals to the azomethine moiety of the dimethylglyoximate fragment giving the chelate ribbed entity that contains both the oxime and hydroxylamine donor groups. Such an unprecedented cage complex of this new encapsulating ligand was thoroughly characterized both in a solution by one- and two-dimensional NMR and in a solid state using X-ray crystallography.