Electro-mediated photoredox catalysis for selective C(sp3)-O cleavages of phosphinates to carbanions

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Tian, Xianhai and Karl, Tobias and Reiter, Sebastian and Yakubov, Shahboz and de Vivie-Riedle, Regina and Koenig, Burkhard and Barham, Joshua (2021) Electro-mediated photoredox catalysis for selective C(sp3)-O cleavages of phosphinates to carbanions. Other. ChemRxiv. (https://doi.org/10.26434/chemrxiv.14753523.v1)

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Abstract

We report a novel example of electro-mediated photoredox catalysis (e-PRC) in the reductive cleavage of C(sp3)-O bonds of phosphinates to alkyl carbanions. As well as deoxygenations, olefinations are reported which are E-selective and can be made Z-selective in a tandem reduction/photosensitization process where both steps are photoelectrochemically promoted. Spectroscopy, computation and catalyst structural variations reveal that our new naphthalene monoimide-type catalyst allows for a more intimate dispersive precomplexation of its radical anion form with the phosphinate substrate, facilitating a reactivity-determining C(sp3)-O cleavage. Surprisingly and in contrast to previously reported photoexcited radical anion chemistries, our conditions i) tolerate aryl chlorides/bromides and ii) do not give rise to Birch-type reductions.

ORCID iDs

Tian, Xianhai, Karl, Tobias, Reiter, Sebastian, Yakubov, Shahboz, de Vivie-Riedle, Regina, Koenig, Burkhard and Barham, Joshua ORCID logoORCID: https://orcid.org/0000-0003-1675-9399;
CORE (COnnecting REpositories)