The Influence of Substitution on Thiol-Induced Oxanorbornadiene Fragmentation

Oxanorbornadienes (ONDs) undergo facile Michael addition with thiols and then fragment by a retro-Diels-Alder (rDA) reaction, a unique two-step sequence among electrophilic cleavable linkages. The rDA reaction rate was explored as a function of the furan structure, with substituents at the 2- and 5-positions found to be the most influential and the fragmentation rate to be inversely correlated with electron-withdrawing ability. Density functional theory calculations provided an excellent correlation with the experimentally measured OND rDA rates.

Automated summary

This study found that in the reactions of oxanorbornadienes, substituents at the 2- and 5-positions have a significant influence on the rate of retro-Diels-Alder reaction, and the fragmentation rate is inversely correlated with electron-withdrawing ability. Density functional theory calculations demonstrated a good correlation with experimentally measured OND rDA rates.