Coordinating Sulfonyl Substrates in Metal-Catalyzed Reactions

Abstract

Metal-coordinating heteroaryl sulfonyl groups, such as the 2-pyridylsulfonyl and the 8-quinolylsulfonyl group, allow the control of the reactivity and stereoselectivity of a great variety of metal-mediated reactions. This concept is rather general and has been applied for the activation of vinyl sulfones and N-sulfonyl imines, as well as in the direct C‒H functionalization of N-H heterocycles. In particular, this kind of coordinating group has played a key role in the enantioselective Rh-catalyzed addition of boronic acids and Cu-catalyzed reduction of 2-pyridyl vinyl sulfones, the Cu-catalyzed addition of organozinc reagents, and the direct Mannich reaction of glycinate imines to N-heteroarylsulfonyl imines. In addition, a general procedure for the Pd-catalyzed C-2 alkenylation of N-(2-pyridylsulfonyl)indoles and pyrroles has been developed.

Keywords:

• Asymmetric catalysis
• C‒H functionalization
• indoles
• Mannich reaction
• pyrroles
• sulfones
• N-sulfonyl imines

Acknowledgments

This work was supported by the Ministerio de Ciencia e Innovación (MICINN, project CTQ2009–07791) and Consejería de Educación de la Comunidad de Madrid (programme AVANCAT; S2009/PPQ-1634). J. H., A. G.-R., and B. U. thank the MICINN for predoctoral fellowships. We thank Johnson Matthey PLC for generous loans of PdCl₂ and Pd(OAc)₂.