A general approach to spirolactonized Si-rhodamines

A general approach has been developed for the synthesis of spirolactonized Si-rhodamines (SiRBs). The alternative synthetic route provides a facile opportunity to access various SiRBs bearing ring-expanded scaffolds and substituents for conjugation. By click reaction, a near-infrared (NIR) mitochondrial tracker was prepared, displaying specific mitochondrial staining in cells.