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

The synthesis of beta-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 beta-arylpyrrolidines is reported. This methodology utilizes 4-aryl-1-sulfony1-1,2,3-triazoles as carbene precursors and the dirhodium tetracarboxylate catalyst Rh-2(S-NTTL)(4). A variety of beta-arylpyrrolidines were prepared in good yields with high levels of diastereo- and enantioselectivity over four linear steps, requiring only a single purification procedure.