BODNs as biocompatible brominating reagents: visible-light photocatalytic tyrosine modification under physiologically favorable conditions.

The photochemical reactivity of 1-bromo-2-oxo-1,2-dihydronaphthalene-1-carboxylates (BODNs) was demonstrated. They are inert in the dark under physiological conditions but become active as brominating reagents for tyrosine modification under visible light irradiation in the presence of a photocatalyst. The BODNs can be applied to protein labeling with bromo groups as sensitive mass tags.