F. Chalier et al., SYNTHESIS, X-RAY GEOMETRY, AND ANODIC BEHAVIOR OF TRIS[2-(HYDROXYMETHYL)PHENYL]PHOSPHANE, Journal of physical chemistry, 100(10), 1996, pp. 4323-4330
Tris[(monohydroxymethyl)phenyl]phosphane 5a and 5b were prepared, and
the geometry of the ortho-isomer 5a was determined by X-ray diffractio
n. 5a was found to be propeller-like in shape, exhibiting a helical co
nformation with the three hydroxymethyl substituents standing on the s
ame side as that with the phosphorus lone pair. Phosphanes 5a and 5b u
nderwent electrochemical one-electron oxidation, giving rise to nonper
sistent phosphoniumyl cation radicals 5a(.+) and 5b(.+). The low value
of the anodic peak potential of 5a was explained by the fast decay of
5a(.+), which was rapidly rearranged to a phosphoranyl radical throug
h the formation of a strong P-.-O bond. The fast oxidation of this int
ermediate phosphoranyl radical followed by a second cyclization led to
the ymethyl)phenyl]spirobi[1H,3H-2,1-benzoxaphosphole] 7a, which was
isolated in significant yield.