Rhodium-Catalyzed Intermolecular C-H Functionalization as a Key Step in the Synthesis of Complex Stereodefined β-Arylpyrrolidines.

The synthesis of β-arylpyrrolidines via a catalytic enantioselective intermolecular allylic C(sp)3-H functionalization of trans-alkenes followed by immediate reduction, ozonolysis, and then in situ diversification of the resulting cyclic hemiaminal to furnish highly substituted, stereoenriched β-arylpyrrolidines is reported. This methodology utilizes 4-aryl-1-sulfonyl-1,2,3-triazoles as carbene precursors and the dirhodium tetracarboxylate catalyst Rh2( S-NTTL)4. A variety of β-arylpyrrolidines were prepared in good yields with high levels of diastereo- and enantioselectivity over four linear steps, requiring only a single purification procedure.