The enantioselective intermolecular sp3 C–H functionalization at allylic and benzylic positions was achieved using rhodium-catalyzed reactions with 4-phenyl-N-methanesulfonyl-1,2,3-triazole. The optimum dirhodium tetracarboxylate catalyst for these reactions was Rh2(S-NTTL)4. The rhodium-bound α-imino carbene intermediates preferentially reacted with tertiary over primary C–H bonds in good yields and moderate levels of enantioselectivity (66-82% ee). This work demonstrates that N-sulfonyltriazoles can be applied to the effective C–H functionalization at sp3 C–H bonds of substrates containing additional functionality.

The synthesis of β-arylpyrrolidines via a catalytic enantioselective intermolecular allylic C(sp)-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 Rh( S-NTTL). 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.

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Rhodium-catalyzed enantioselective synthesis of 1-phenoxycyclopropane-1-carbaldehydes by intermolecular cyclopropanation of terminal alkenes followed by imine hydrolysis is described. This methodology utilizes 4aryloxy-1-sulfonyl-1,2,3-triazoles as the carbene precursors and the chiral dirhodium(II) tetracarboxylates Rh 2 (S-NTTL) 4 or Rh 2 (S-DPCP) 4 as the catalysts. These reactions are considered to proceed via rhodium-stabilized donor/acceptor carbene intermediates, and these studies demonstrate that a heteroatom donor group is compatible with an enantioselective transformation.

The products are often formed with high enantiomeric excess.