The iron-catalyzed oxidative coupling of phenols has emerged as a powerful method for preparing complex phenolic frameworks from simple and readily available compounds. This synopsis describes the selectivity challenges inherent in oxidative coupling reactions while at the same time presents our mechanistic-driven strategy employed to confront them.

A bioinspired iron-catalyzed consecutive oxidative cross-coupling reaction between a single phenolic unit and nucleophilic arenes was developed. This sustainable transformation offers a selective synthetic strategy for the preparation of complex polyaryl compounds directly from readily available phenols. With the aid of electron paramagnetic resonance spectroscopy, it was demonstrated that the groups ortho to the phenolic functionality (whether hydrogen, methyl, or methoxy) direct the regioselectivity (ortho, para, or meta via dienone-phenol rearrangement) and chemoselectivity (C-C coupling or C-O coupling) in this multistep process.

A novel type of chiral redox disulfonate iron complex for asymmetric catalysis is reported. The [Fe((R a )-BINSate)] + (BINSate = 1,1′binaphthalene-2,2′-disulfonate) complex effectively promotes the enantioselective oxidative cross-coupling between 2-naphthols (1) and 2-aminonaphthalene derivatives (2), affording optically enriched (R a )-2-amino-2′hydroxy-1,1′-binaphthyls (NOBINs) with exceptional yields and enantioselective ratios (up to 99% yield and 96:4 er). The [Fe((R a )-BINSate)] + catalyst was designed as a chiral version of FeCl 3 with multicoordination sites available for binding the two coupling partners 1 and 2 as well as the oxidant. Our structure−selectivity and activity study, which covered most of the important positions in the NOBIN scaffold, revealed the effect of different substitution patterns on the coupling efficiency and stereoselectivity.

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