Selective E to Z isomerization of 1,3-Dienes Enabled by A Dinuclear Mechanism

Abstract

AbstractTheE/Zstereocontrol in a C=C bond is a fundamental issue in olefin synthesis. Although the thermodynamically more stableEgeometry is readily addressable by thermalZtoEgeometric isomerization through equilibrium, it has remained difficult to undergo thermal geometric isomerization to the reverseEtoZdirection in a selective manner, because it requires kinetic trapping ofZ-isomer with injection of chemical energy. Here we report that a dinuclear PdI−PdIcomplex mediates selective isomerization ofE-1,3-diene to itsZ-isomer without photoirradiation, where kinetic trapping is achieved through rational sequences of dinuclear elementary steps. The chemical energy required for theEtoZisomerization can be injected from an organic conjugate reaction through sharing of common Pd species.