Related Experiment Video
Updated: Jun 16, 2025
![[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)
[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
Published on: May 21, 2019
Interrogating Explicit Solvent Effects on the Mechanism and Site-Selectivity of Aryl Halide Oxidative Addition to
Jingru Lu1, Holly Celuszak1, Irina Paci1
1Department of Chemistry, University of Victoria, 3800 Finnerty Rd., Victoria, BC V8P 5 C2, Canada.
Solvent polarity and basicity significantly influence palladium-catalyzed oxidative addition rates and selectivity. Hydrogen bonding impacts reactivity, while polar solvents favor specific mechanisms for electron-deficient pyridines and triflates.
Area of Science:
- Organometallic Chemistry
- Catalysis
- Reaction Mechanism
Background:
- Palladium complexes are crucial catalysts in organic synthesis.
- Oxidative addition is a key step in many palladium-catalyzed cross-coupling reactions.
- Solvent effects on reaction kinetics and selectivity are not fully understood for all substrate classes.
Purpose of the Study:
- To investigate the impact of solvent properties on the rate, selectivity, and mechanism of oxidative addition to L2Pd(0) species.
- To elucidate the role of solvent basicity and polarity in reactions involving (hetero)aryl (pseudo)halides.
- To understand how substrate electronic properties and solvent interactions dictate reaction outcomes.
Main Methods:
- Studied oxidative addition of various (hetero)aryl (pseudo)halides to Pd(PCy3)2.
- Varied solvent polarity and basicity to assess effects on reaction kinetics and site-selectivity.
- Analyzed reaction mechanisms based on observed trends in rate and selectivity.
Main Results:
- 2-chloro-3-aminopyridine showed faster oxidative addition in toluene (less polar) due to solvent basicity and hydrogen bonding, contrary to other 2-halopyridines.
- Electron-deficient multihalogenated pyridines displayed improved site-selectivity in polar solvents, favoring nucleophilic displacement over 3-centered transition states.
- (Hetero)aryl triflates reacted faster in polar solvents, indicating highly polar transition states and enhanced C-OTf oxidative addition selectivity.
Conclusions:
- Solvent effects, including basicity and polarity, are critical determinants of oxidative addition rates and selectivity in palladium catalysis.
- Hydrogen bonding interactions can significantly alter reactivity trends for specific substrates.
- Understanding solvent-ligand-substrate interactions is key to controlling palladium-catalyzed reactions for diverse (hetero)aryl halides and triflates.
More Related Videos
09:54Chemoselective Preparation of 1-Iodoalkynes, 1,2-Diiodoalkenes, and 1,1,2-Triiodoalkenes Based on the Oxidative Iodination of Terminal Alkynes
Published on: September 12, 2018
12:08Catalytic Reactions at Amine-Stabilized and Ligand-Free Platinum Nanoparticles Supported on Titania During Hydrogenation of Alkenes and Aldehydes
Published on: June 24, 2022
Related Concept Videos
Regioselectivity of Electrophilic Additions-Peroxide Effect
Radical Anti-Markovnikov Addition to Alkenes: Overview
E2 Reaction: Kinetics and Mechanism
E1 Reaction: Kinetics and Mechanism
Nucleophilic Aromatic Substitution: Elimination–Addition
Regioselectivity of Electrophilic Additions to Alkenes: Markovnikov's Rule
The hydrohalogenation of an unsymmetrical alkene can yield two haloalkane products, depending on which vinylic carbon takes up the halogen. However, one product usually predominates, where hydrogen adds to the vinylic carbon bearing the...