Due to experiencing a challenging dearomatization process, the aromatic sigmatropic rearrangement of allyl naphthyl ethers is a difficult yet efficient method to build useful naphthalenone skeletons. Here, we report a -Claisen rearrangement-based asymmetric dearomatization of allyl α-naphthol ethers enabled by a ,'-dioxide/Co complex. A variety of naphthalenones were obtained in moderate to good yields with good to excellent ee values. Interestingly, by exchanging the allyl group on the ether and that at the -position of the benzene ring, enantiodivergent synthesis can be achieved. Experimental studies and DFT calculations revealed that aryl allyl ethers tend to transform a stepwise allyl π-complex migration pathway, while, alkyl allyl ethers transformed through a concerted -Claisen rearrangement/Cope rearrangement sequence.
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| http://dx.doi.org/10.1039/d3sc05677e | DOI Listing |
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