Comparative Study of Homocoupling Reactions to Create 2,2'-bipyridine Adducts
Abstract
The project focuses on investigating the synthesis of 2,2’-bipyridine adducts for potential use as ligands in novel organometallic ruthenium complexes. The bipyridine building blocks, based on their excellent bidentate ligands with complexing abilities, will be incorporated into ruthenium complexes in a collaborative project, increasing the photosensitivity of these complexes, and opening the doors for many applications, ranging from synthetic photovoltaics to anti-cancer activity.
The aim of this study was to optimize the preparation of the 2,2’-bipyridine adducts. Prior studies conducted in our lab have compared several homo and cross coupling reactions. It was determined that homocoupling offers a more efficient route, providing greater yield as well as the desired symmetrical bipyridine adducts of 6,6’-(1H-pyrazol-1-yl)-2,2’-bipyridine, 2,2′-bipyridine-3,3′-diol, 4,4’-dimethyl-2,2’-bipyridine, and 5,5’-dimethyl-2,2’-bipyridine. Comparative analysis between 2-bromo-6-(1H-pyrazol-1-yl) pyridine, 2-bromo-3-hydroxypyridine, 2-bromo-4-methylpyridine, and 2-bromo-5- methylpyridine allowed observation of the effects of different electron donating substituents on the synthesis of 2,2’-bipyridine adducts. Additionally, the effects of two different palladium-based catalysts on each substrate were compared: tetrakis(triphenylphosphine) palladium (0) and bis(triphenylphosphine) palladium (II) chloride.
The procedure was conducted under an inert, moisture-free environment. The reaction chamber was assembled in a glovebox protecting the air-sensitive catalysts and substrates and was then moved onto a Schlenk-line assembly under inert argon atmosphere. Reaction times varied from 12 to 72 hours based on the starting substrate and the reaction progress was monitored with thin layer chromatography. Final products were isolated and purified via acidic extraction, and if needed recrystallization. Compound characterization was carried out utilizing NMR and FT-IR.
Faculty Sponsors
Dr. Beatrix Aukszi
Project Type
Event
Location
Alvin Sherman Library
Start Date
4-6-2022 12:00 PM
End Date
4-7-2022 5:00 PM
Comparative Study of Homocoupling Reactions to Create 2,2'-bipyridine Adducts
Alvin Sherman Library
The project focuses on investigating the synthesis of 2,2’-bipyridine adducts for potential use as ligands in novel organometallic ruthenium complexes. The bipyridine building blocks, based on their excellent bidentate ligands with complexing abilities, will be incorporated into ruthenium complexes in a collaborative project, increasing the photosensitivity of these complexes, and opening the doors for many applications, ranging from synthetic photovoltaics to anti-cancer activity.
The aim of this study was to optimize the preparation of the 2,2’-bipyridine adducts. Prior studies conducted in our lab have compared several homo and cross coupling reactions. It was determined that homocoupling offers a more efficient route, providing greater yield as well as the desired symmetrical bipyridine adducts of 6,6’-(1H-pyrazol-1-yl)-2,2’-bipyridine, 2,2′-bipyridine-3,3′-diol, 4,4’-dimethyl-2,2’-bipyridine, and 5,5’-dimethyl-2,2’-bipyridine. Comparative analysis between 2-bromo-6-(1H-pyrazol-1-yl) pyridine, 2-bromo-3-hydroxypyridine, 2-bromo-4-methylpyridine, and 2-bromo-5- methylpyridine allowed observation of the effects of different electron donating substituents on the synthesis of 2,2’-bipyridine adducts. Additionally, the effects of two different palladium-based catalysts on each substrate were compared: tetrakis(triphenylphosphine) palladium (0) and bis(triphenylphosphine) palladium (II) chloride.
The procedure was conducted under an inert, moisture-free environment. The reaction chamber was assembled in a glovebox protecting the air-sensitive catalysts and substrates and was then moved onto a Schlenk-line assembly under inert argon atmosphere. Reaction times varied from 12 to 72 hours based on the starting substrate and the reaction progress was monitored with thin layer chromatography. Final products were isolated and purified via acidic extraction, and if needed recrystallization. Compound characterization was carried out utilizing NMR and FT-IR.
