Unraveling the Photodeprotection Mechanism of Anthraquinon-2-ylmethoxycarbonyl-Caged Alcohols Using Time-Resolved Spectroscopy

• DOI: 10.1021/acs.joc.8b02252
• Publication Date: 2018-10-10T17:56:31Z
• Authors: Yan Guo; Qingqing Song; Jialin Wang; Jiani Ma; Xiting Zhang; David Lee Phillips
• Keywords: Decarboxylation; Anthraquinones; Ketyl; Reactive intermediate

Anthraquinone (AQ) compounds have been used as photolabile protecting groups (PPGs) to protect alcohols, ketones, and carboxylic acids. However, because of the lack direct spectroscopic information for transient species intermediates related with deprotection reaction(s), photorelease mechanism(s) these systems are still largely unknown. In this contribution, we detail a time-resolved investigation using anthraquinone-protected galactose (1) adenosine (2) investigate photodeprotection reaction kinds AQ-PPGs. It was found that, in THF-H2O solvents, ketyl radical generated 1 2 be reactive intermediate that then formed dihydroxyanthracene species. The occurred accompaniment decarboxylation process. These results provide an improved understanding how AQ-PPGs work will help assist design applications selected anthraquinone derivatives PPG platform, especially aqueous environments more relevant use biological systems.