Related Experiment Video
Updated: Mar 22, 2026

Palladium N-Heterocyclic Carbene Complexes: Synthesis from Benzimidazolium Salts and Catalytic Activity in Carbon-carbon Bond-forming Reactions
Published on: July 30, 2017
Pre-transmetalation intermediates in the Suzuki-Miyaura reaction revealed: The missing link
Andy A Thomas1, Scott E Denmark2
1Roger Adams Laboratory, Department of Chemistry, University of Illinois, Urbana, IL 61801, USA.
Abstract:
Despite the widespread application of Suzuki-Miyaura cross-coupling to forge carbon-carbon bonds, the structure of the reactive intermediates underlying the key transmetalation step from the boron reagent to the palladium catalyst remains uncertain. Here we report the use of low-temperature rapid injection nuclear magnetic resonance spectroscopy and kinetic studies to generate, observe, and characterize these previously elusive complexes. Specifically, this work establishes the identity of three different species containing palladium-oxygen-boron linkages, a tricoordinate boronic acid complex, and two tetracoordinate boronate complexes with 2:1 and 1:1 stoichiometry with respect to palladium. All of these species transfer their boron-bearing aryl groups to a coordinatively unsaturated palladium center in the critical transmetalation event.
More Related Videos
Related Concept Videos
Alkenes via Reductive Coupling of Aldehydes or Ketones: McMurry Reaction
Nucleophilic Aromatic Substitution: Addition–Elimination (SNAr)
The reaction begins with an attack of the nucleophile on the carbon that holds the leaving group. This results in the delocalization of the π electrons over the ring carbons. The resonance interaction between...
Preparation and Reactions of Sulfides
Reduction of Alkynes to trans-Alkenes: Sodium in Liquid Ammonia
When dissolved in liquid ammonia, an alkali metal, such as sodium,...
Olefin Metathesis Polymerization: Overview
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
Nucleophilic Aromatic Substitution: Elimination–Addition

