17O and 11B NMR spectroscopic study of substituted benzo[d]-2,2-difluoro-1,3,2-oxoniaoxaboratins

¹⁷O NMR data are reported for 10 benzod]-2,2-difluoro-1,3,2-oxoniaoxaboratins derived from various ortho-hydroxyacetophenones and for 2,2-difluoro-1,3,2-oxoniaoxaboratins derived from related hydroxyacetyl naphthalenes and hydroxybenzophenones. The signal for the carbonyl-like oxygen for these compounds is substantially shielded and appears at 288 ± 22 δ. The single bonded oxygen signal for the 1,3,2-oxoniaoxaboratins appears at 122 ± 6 δ, except for the naphthalene analogs, whose signal appears at 146 ± 10 δ. The ¹¹B NMR signal for these compounds is insensitive to structural changes and appears at 0.85 ± 0.25 δ. © 1995 John Wiley & Sons, Inc.