Asymmetric, visible light-mediated radical sulfinyl-Smiles rearrangement to access all-carbon quaternary stereocentres

The asymmetric construction of all-carbon quaternary centres within acyclic settings represents a long-standing challenge for synthetic chemists. Alongside polar and radical methods, rearrangement reactions represent an attractive platform, but still broadly applicable methods are in high demand. Here we report an asymmetric, radical sulfinyl-Smiles rearrangement to access acyclic amides that bear an alpha-all-carbon quaternary centre. Our strategy uses enantioenriched N-arylsulfinyl acrylamides as acceptors for a variety of radicals produced in situ under mild photoredox conditions. The sulfinamido group not only directs the 1,4-migration of the aryl moiety onto the alpha-carbon of the amide, which thus governs its absolute configuration, but also functions as a traceless chiral auxiliary. The amides obtained in this multicomponent process are prevalent in pharmaceuticals, agrochemicals and bioactive natural products, and can be transformed into valuable chiral alpha,alpha-disubstituted acids, oxindoles as well as into beta,beta-disubstituted amines, highlighting the synthetic potential of this transformation. The assembly of a single configuration of an all-carbon quaternary centre within acyclic systems remains a challenge for synthetic chemists. Now, it has been shown that alpha-all-carbon quaternary centres can be installed in acyclic amides, with excellent levels of absolute stereocontrol, through a radical sulfinyl Truce-Smiles rearrangement.