tert-Butyl nitrite as a mild nitrosylation agent for pyrroles.

A new nitrosylation reaction for pyrroles, featuring tert-butyl nitrite as a mild nitrosylation agent, has been developed. Application to a variety of diaryl-substituted pyrroles resulted in moderate to good yields with significant improvement, in comparison to previous methods, for pyrroles featuring aryl groups appended with electron-donating groups. Isolation and characterisation of a nitrosopyrrole featuring tert-butyl functionality on the pyrrole ring was achieved in excellent yield, while attempts to nitrosylate other alkyl-functionalised pyrroles yielded trace amounts of promising oxime-containing products.