Scott Denmark

TRANSMETALATION IN THE SUZUKI-MIYAURA CROSS-COUPLING REACTION: MECHANISTIC INSIGHTS AND PREPARATIVE IMPLICATIONS

The Suzuki-Miyaura reaction is by far the most commonly practiced and most powerful of the palladium catalyzed cross-coupling reactions. This reaction owes its widespread utility to the vast number of commercially available boronic acids and boronate derivatives as well as the mildness of the reaction conditions and the vast array of ligands that have allowed the coupling of unreactive and challenging substrates. Nevertheless, the molecular details of the critical transmetalation step have remained obscure because of the extreme reactivity of the hypothetical pretransmetalation intermediate containing the key B–O–Pd linkage. Through the

combination of spectroscopic analysis, independent synthesis, and kinetic measurements, we have unambiguously identified and characterized the elusive, pretransmetalation species that undergo the Suzuki-Miyaura cross-coupling reaction from various boron derivatives.