Reactions of PhIX2 I(iii) oxidants with heavy triphenyl pnictines

Abstract

The reactions of [PhI(pyridine)₂]²⁺, PhI(OAc)₂ and PhI(OTf)(OAc) with Ph₃As, Ph₃Sb and Ph₃Bi are described. The reactions of [PhI(pyridine)₂]²⁺ with Ph₃Sb and Ph₃Bi afford dicationic Pn(V) complexes ligated by pyridine in one step. These were previously reported by Burford in multi-step syntheses. Reactions with PhI(OAc)₂, which were already known for Sb and Bi giving Pn(V) diacetates, were confirmed to give the same type of compound for As. Reactions with PhI(OAc)(OTf) were less selective, resulting in the isolation of iodonium cations [Ph–I–Ph]⁺ for As and Bi, while Ph₃Sb gave an oxobridged di-antimony species characteristic of the decomposition of a high valent triflate bound species.