Structural and electronic information on two solid iminophosphoranes, obtained from NMR

Abstract

Neste trabalho foram obtidos os espectros de RMN CPMAS de fósforo-31 e carbono-13 do imino(trifenil)fosforano e do brometo de amino(trifenil)fosfônio. A análise detalhada desses espectros forneceu informações sobre o tensor de blindagem de 31 P e o tensor de acoplamento quadrupolar de 14 N. O espectro estático de 31 P do brometo foi também analisado em termos dos tensores relevantes. Os cálculos ab initio no nível hf/6-31g* reproduzem bem os dados observados, com exceção dos deslocamentos isotrópicos, os quais requerem cálculos com bases maiores e/ou de um nível teórico superior. As orientações dos tensores na estrutura do brometo foram derivadas através dos cálculos. Phosphorus-31 and carbon-13 CPMAS NMR spectra have been obtained for imino(triphenyl)phosphorane and amino(triphenyl)phosphonium bromide. Detailed analysis yields information about the 31 P shielding tensor and the 14 N quadrupole coupling tensor. The static 31 P spectrum of the bromide was also analysed in terms of the relevant tensors. Ab initio calculations at the hf/6-31g* level reproduce the observed data well, except for the isotropic shifts, which require a larger basis set and/or higher level of theory. The orientations of the tensors in the molecular frame are derived for the bromide from the calculations.

Construction of Benzo-1,2,3-thiazaphosphole Heterocycles by Annulations of ortho-Phosphinoarenesulfonyl Fluorides with Trimethylsilyl Azide

“…Pathway A was ruled out due to no formation of the expected tosyl azide 7a (Scheme , eq 1). Moreover, the detection of iminophosphorane 7b suggested that a Staudinger-type intermediate was likely involved (Scheme , eq 2), which supported pathway D . Additional evidence was brought from a trapping experiment in which the product 7d was obtained (Scheme , eq 3).…”