Catalyst-free regioselective sulfonylation of phenoxazine with sulfonyl hydrazides in H2O/HFIP

Abstract

A facile catalyst-free sulfonylation of phenoxazine with sulfonyl hydrazides was efficiently developed in H₂O/HFIP without any catalyst. This metal- and catalyst-free protocol is suitable for aromatic and aliphatic reagents to afford the corresponding sulfones in moderate to high yields. A gram-scale experiment was performed to assess the practicability of the method.