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Please login or sign up for a free trial to access the full content. Method 2: Photoinduced Electron Transfer between Tetrachlorobenzo-1,4-quinone and Benzodioxoles

DOI: 10.1055/sos-SD-022-00806

Lebel, H.; Grenon, M.Science of Synthesis, (200522685.

When tetrachlorobenzo-1,4-quinone is irradiated with ultraviolet light in the presence of substituted benzodioxoles acting as an electron donor, electron transfer occurs, to give cyclic aromatic ortho esters 35 in high yields (Scheme 20).[‌81‌] Either a polar exciplex or a contact ion-radical pair (CIP) is formed when benzene is the solvent, or a solvent separated ion-radical pair (SSIP) is generated in a more polar medium such as acetonitrile. Hydrogen transfer, or proton transfer, leads to a semiquinone-benzodioxolyl radical pair, which then gives the ortho ester after radical pair recombination.

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