Several phosphepine oxides were synthesised in optically pure form. Sharpless asymmetric dihydroxylation was used to introduce the chiral centres in all cases. Ring closure was achieved using either PhPCl2 or PrPCl2 together with a double nucleophile generated by either a double ortho-lithiation or double bromineâlithium exchange. The X-ray crystal structures of three phosphepine oxides illustrate their different conformations. The NMR spectra of several phosphepine oxides are described as is the chemistry which is shown to differ from that of acyclic phosphine oxides.
Synthesis and chemistry of enantiomerically pure 10,11-dihydrodibenzo[b,f]thiepines
作者:Paul Wyatt、Andrew Hudson、Jonathan Charmant、A. Guy Orpen、Hirihattaya Phetmung
DOI:10.1039/b516606c
日期:——
Several chiral thiepines were efficiently constructed using sulfur diimidazole in combination with a variety of bislithiated carbon fragments. The sulfur atom in these thiepines is found to be unusually unreactive compared to diphenylsulfide.