Light-Driven Intermolecular Charge Transfer Induced Reactivity of Ethynylbenziodoxol(on)e and Phenols

Ethynylbenziodoxol­(on)­es
(EBXs) have been widely used in organic
synthesis as electrophilic alkyne-transfer reagents involving carbon-
and heteroatom-based nucleophiles. However, potential reactions of
EBXs with phenols remain uninvestigated. Here, we present the formation
of (Z)-2-iodovinyl phenyl ethers with excellent regio-
and stereoselectivity through the reactivity between EBXs and phenols
driven by visible light. We propose that this light-activated transformation
proceeds through electron donor–acceptor complexes to enable
new reactivity beyond existing mechanisms for alkynylation of carbon-
and heteroatom-based nucleophiles. This operationally robust process
was employed for the synthesis of diverse (Z)-2-iodovinyl
phenyl ethers through irradiating a solution containing a phenyl-EBX,
a phenol, and the base Cs2CO3 with a commercially
available blue LED at room temperature. The (Z)-2-iodovinyl
phenyl ether products can be further stereospecifically functionalized
to form trisubstituted alkenes, demonstrating the potential of these
products en route to chemical complexity.