Thiol-Promoted Selective Addition of Ketones to Aldehydes
journal contributionposted on 21.11.2014, 00:00 by Regev Parnes, Sachin Narute, Doron Pappo
A simple and efficient thiol-mediated addition of ketones to aromatic and aliphatic aldehydes is reported. This thermodynamically controlled Pummerer/aldol reaction, which can tolerate both moisture and protic functional groups, provides a direct entry to syn-β-thioketones in high chemo- and regioselectivity. Mechanistic studies revealed that selective transformation of the aldehyde to an electrophilic thionium ion species concurrent with the generation of a nucleophilic vinyl sulfide coupling partner from the ketone is imposing cross-coupling over dimerization.