Facile and General Synthesis of Photoactivatable Xanthene Dyes

摘要

Photoactivatable "caged" fluorophores enable numerous advanced biological imaging experiments, including photo-activated localization microscopy (PALM) and related super-resolution imaging techniques. Of the extant fluoro-phore scaffolds, caged rhodamines and fluoresceins display properties that are exceptionally well suited for super-resolution microscopy, exhibiting high contrast and photon yields. The utility of these probes in PALM imaging has been hampered, however, by inefficient syntheses. For example, the existing route to caged Q-rhodamine, a promising PALM probe, requires harsh, strongly basic conditions and is reported to "generate many products" with yields given as "poor" and "variable". Such difficult, inefficient syntheses have rendered these important caged molecules unavailable to the scientific community.