A Natural Alkaloid, β-Carboline, as a One- and Two-Photon Responsive Fluorescent Photoremovable Protecting Group: Sequential Release of the Same or Different Carboxylic Acids.

The β-carboline moiety, substituted at the C1 and C3 benzylic positions with a leaving group, has been demonstrated for the first time as a photoremovable protecting group for time-dependent sequen...