We report here a catalytic method for the modular ring expansion of cyclic aliphatic alcohols. In this work, proton-coupled electron transfer activation of an allylic alcohol substrate affords an alkoxy radical intermediate that undergoes subsequent C-C bond cleavage to furnish an enone and a tethered alkyl radical. Recombination of this alkyl radical with the revealed olefin acceptor in turn produces a ring-expanded ketone product. The regioselectivity of this C-C bond-forming event can be reliably controlled via substituents on the olefin substrate, providing a means to convert a simple N-membered ring substrate to either n+1 or n+2 ring adducts in a selective fashion.
We report here a catalytic method for the modular ring expansion of cyclic aliphatic alcohols. In this work, proton-coupled electron transfer activation of an allylic n class="Chemical">alcohol substrate affords an alkoxy radical intermediate that undergoes subsequent C-C bond cleavage to furnish an enone and a tethered alkyl radical. Recombination of this alkyl radical with the revealed olefin acceptor in turn produces a ring-expanded ketone product. The regioselectivity of this C-C bond-forming event can be reliably controlled via substituents on the olefin substrate, providing a means to convert a simple N-membered ring substrate to either n+1 or n+2 ring adducts in a selective fashion.
Authors: Philip R D Murray; James H Cox; Nicholas D Chiappini; Casey B Roos; Elizabeth A McLoughlin; Benjamin G Hejna; Suong T Nguyen; Hunter H Ripberger; Jacob M Ganley; Elaine Tsui; Nick Y Shin; Brian Koronkiewicz; Guanqi Qiu; Robert R Knowles Journal: Chem Rev Date: 2021-11-23 Impact factor: 60.622