A practical CO₂-mediated synthesis of 5,6-carboxylated silicon-rhodamines for targeted probe development

• Dongjie Hou,
• Shaowei Wu,
• Ning Xu,
• Pengjun Bao,
• Wenhao Jia,
• Qinglong Qiao and
• Zhaochao Xu

Beilstein J. Org. Chem. 2026, 22, 915–924, doi:10.3762/bjoc.22.72

• .22.72 Abstract Silicon-rhodamine (SiR) dyes are among the most important fluorophores for super-resolution imaging owing to their far-red emission, high photostability, and tunable lactone–zwitterion equilibrium. However, their broader application in targeted probe development has been limited by the

• one-pot access to HaloTag-targeted SiR probes. The resulting probes were successfully applied to long-term live-cell super-resolution imaging, allowing visualization of filopodial dynamics and mitochondrial remodeling. This work establishes a concise and efficient route to functionalized SiR dyes and

• facilitates the rapid development of targeted SiR probes. Keywords: carboxylation; CO2; fluorescent probes; silicon-rhodamine; super-resolution imaging; Introduction Rhodamine dyes, which enable fluorescence imaging in living cells – a powerful technique for studying biological systems in vivo [1][2] – have