Abstract
A systematic series of triarylbismuthane oxides was prepared in order
to disclose their structure and reactivity, which have been compared
with those of lighter pnictogen counterparts. X-ray crystallographic
analysis of tris(2-methoxyphenyl)bismuthane oxide and
tris(2-methoxyphenyl)stibane oxide revealed that they exist as dimers
with a flat bis(μ-oxo) ring, implying that the polarized
Bi+–O− and
Sb+–O− bonds aggregate to attain
electrostatic stabilization. In sharp contrast to their phosphorus,
arsenic, and antimony counterparts, triarylbismuthane oxides are
thermally unstable and possess a high oxidizing ability. In
particular, the bismuthane oxides bearing ortho-substituted aryl
ligands oxidized primary and secondary alcohols to aldehydes and
ketones, respectively, with high efficiency under mild conditions.