Syntheses and properties of phosphino- and phosphinatopyrroles

The syntheses of PN bonded pyrrolyl- and 2,5-dimethylpyrrolylphosphines (x = 0-2) and the oxy derivatives py 3 PO and (Me 2 py) 2 P(O)Cl by the reaction of potassium pyrrolide or 2,5-dimethylpyrrolide with an appropriate chlorophosphine or with POCl 3 are described. Molecular structures were inferred from spectroscopic data. The PN bonded phosphines are stable to solvolytic attack by water or alcohols and do not undergo insertion reactions with CS 2 , but they are oxidised by oxygen and suffer nucleophilic displacement of the azole moiety by strong base. The Lewis acid BCl 3 cleaves the PN bond and CH 3 I reacts with only one member, to form a phosphonium salt. Hindered rotation about the PN bond was detected in the (2,5-dimethylpyrrolyl)phosphine series, but not among the corresponding oxy derivatives. The nature of the PN bond and trends in the basicity of the phosphorus atom are discussed.