HNO3/HFIP: A Nitrating System for Arenes with Direct Observation of pi-Complex Intermediates

This report describes an efficient nitrating system for the nitration of arenes at room temperature by using an equivalent of nitric acid in HFIP (1,1,1,3,3,3-hexafluoroisopropanol). The pi-complex intermediate of an arene with a nitronium ion stabilized by HFIP can be directly observed by UV vis spectra and is supported by theoretical calculations.