ChemistrySelect, vol.8, no.18, 2023 (SCI-Expanded)
A computational study on the reaction mechanism of the effective synthesis of sulfonated benzo[b]oxepinones and chromanes by radical cascade cyclization is carried out employing the density functional theory (DFT). Based on our computations, the rate-determining step is the formation of arylsulfonyl radical for the reaction scheme. Our calculations show that the reaction of 1,8- and 1,7-enynes with arylsulfonyl radical proceeds by forming more thermodynamically stable intermediates. Therefore, 1,8-enynes prefer 7-exo-trig cyclization, while 1,7-enynes prefer 6-exo-trig cyclization. Our computations are consistent with experimental results of the radical cascade cyclization of 1,8- and 1,7-enynes. Moreover, our computations show that if the reaction is carried out in a proton-free solvent, the elimination product can be obtained from the cascade radical cyclization of the 1,7-enyne.