Unexpected Staudinger reaction of α-azidoacetonitriles α-phenyl substituted with triphenylphospine. Preparation, X-ray crystal and molecular structures of a phosphazine, an aminophosphonium carbanion salt and a phosphazide, with (Z)-configuration

Article abstract of DOI:10.1016/0040-4020(96)00499-1

Staudinger reaction of α-azidophenylacetonitrile with triphenylphosphine in 1:2 molar ratio provides the triphenylphosphazine 4 derived from α-diazophenylacetonitrile, whereas 2:1 molar ratio the final product is found to be the aminotriphenylphosphonium salt of phenylmalononitrile 6. However, the Staudinger reaction of α- azidodiphenylacetonitrile with triphenylphosphine affords the corresponding (Z)-phosphazide 17. The crystal and molecular structures of compounds 4,6, and 17 have been determined by X-ray analysis. Compound 17 is the first isolated phosphazide which presents the (Z)-configuration with respect to the central N,N bond of the PN₃C moiety (P-N-N-N= 0.0(3)°).