Harnessing Thorpe-Ingold Dialkylation to Access High-Hill-Percentage pH Probes

作者：Xiao, Yansheng; Huang, Yunxia; Zeng, Zhenhua; Luo, Xiao^*; Qian, Xuhong; Yang, Youjun^*

来源：Journal of Organic Chemistry, 2022, 87(1): 85-93.

DOI：10.1021/acs.joc.1c01887

• FLUORESCENT SENSORS
• COOPERATIVITY
• AMPLIFICATION

Sensitivity is an important parameter for a molecular probe. Hill-type pH probes exhibit improved detection sensitivity compared to the traditional pH probes following the Henderson-Hasselbalch equation. Exploiting positive cooperativity, we recently devised a novel molecular scaffold (PHX) to offer such an unconventional Hill-type pH titration profile. We previously confirmed that PHX is not a pure Hill-type probe yet. Only 64% of its absorbance/fluoresce nce turn-on is the result of a Hill-type pathway. The remaining 36% is from an undesired Henderson-Hasselbalch-type pathway (HH pathway). In this work, the Thorpe-Ingold dialkylation was harnessed to further suppress the percent contribution of the HH pathway down to 16%. We also propose that PHX is a viable molecular model for assessing the efficacy of the steric compressing effect induced by different Thorpe-Ingold dialkylations.

• 单位
  华东理工大学