Highly regioselective ferrocenyl cyclohexene/cyclopentene isomerization through benzyne transfer coupling

Highly regioselective ferrocenyl cyclohexene/cyclopentene isomerization through hexadehydro-Diels-Alder (HDDA) benzyne transfer coupling is developed. The tetraynes result in the formation of an aryne through the HDDA reaction which is then in situ trapped by ferrocene-tethered cyclohexene/cyclopentene under mild conditions without a catalyst. The density functional theory (DFT) calculations reveal that the Alder-ene reaction process is the key to obtaining functionalized ferrocene derivatives with high regioselectivity and excellent yields by a 1,3-transposition of the involved alkenes. This work expands the coupling reaction between arynes and cyclic alkenes, further providing an innovative approach for the synthesis of ferrocene derivatives.

Automated summary

Highly regioselective ferrocenyl cyclohexene/cyclopentene isomerization is achieved through hexadehydro-Diels-Alder (HDDA) benzyne transfer coupling. The reaction proceeds under mild conditions without a catalyst, with tetraynes forming aryne intermediates that are then trapped by ferrocene-tethered cyclohexene/cyclopentene. Density functional theory (DFT) calculations reveal that the key step in the process is the Alder-ene reaction, which allows for the synthesis of functionalized ferrocene derivatives with high regioselectivity and excellent yields. This study expands the coupling reaction between arynes and cyclic alkenes, providing an innovative approach for the synthesis of ferrocene derivatives.