Intramolecular C–H functionalization has been established as a facile and reliable entry into heterocyclic systems. This report from the Sarpong group extend this technology, describing the synthesis of poly-substituted saturated heterocyclic systems that incorporate both aromatic and aliphatic side chains.
Using N-sulfonyltriazoles as Rh(II) azavinyl carbene equivalents a diverse array of cis-2,3-substituted tetrahydrofurans were accessible. The stereoinduction of this reaction was found to be highly dependent on the catalyst ligand environment; the greater the steric congestion, the more pronounced the preference for the cis isomer. Use of the triazole as a carbene precursor introduces a versatile functionality to the C–H functionalization product, one that the Sarpong group use to good effect to rapidly access tricyclic scaffolds reminiscent of many natural product skeletons.