Benzimidazole and Related Ligands for Cu-Catalyzed Azide−Alkyne Cycloaddition

Tris(2-benzimidazolylmethyl)amines have been found to be superior accelerating ligands for the copper(I)-catalyzed azide−alkyne cycloaddition reaction. Candidates bearing different benzimidazole N-substituents as well as benzothiazole and pyridyl ligand arms were evaluated by absolute rate measureme...

Full description

Saved in:
Bibliographic Details
Published in:Journal of the American Chemical Society 2007-10, Vol.129 (42), p.12696-12704
Main Authors: Rodionov, Valentin O, Presolski, Stanislav I, Gardinier, Sean, Lim, Yeon-Hee, Finn, M. G
Format: Article
Language:English
Subjects:
Alkynes - chemistry
Azides - chemistry
Benzimidazoles - chemistry
Buffers
Calorimetry - methods
Catalysis
Chemistry, Organic - methods
Copper - chemistry
Hydrogen-Ion Concentration
Kinetics
Ligands
Models, Chemical
Molecular Structure
Time Factors
Triazoles - chemistry
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Tris(2-benzimidazolylmethyl)amines have been found to be superior accelerating ligands for the copper(I)-catalyzed azide−alkyne cycloaddition reaction. Candidates bearing different benzimidazole N-substituents as well as benzothiazole and pyridyl ligand arms were evaluated by absolute rate measurements under relatively dilute conditions by aliquot quenching kinetics and by relative rate measurements under concentrated conditions by reaction calorimetry. Benzimidazole-based ligands with pendant alkylcarboxylate arms proved to be advantageous in the latter case. The catalyst system was shown to involve more than one active species, providing a complex response to changes in pH and buffer salts and the persistence of high catalytic rate in the presence of high concentrations of coordinating ligands. The water-soluble ligand (BimC 4 A) 3 was found to be especially convenient for the rapid and high-yielding synthesis of several functionalized triazoles with 0.01−0.5 mol % Cu.
ISSN:0002-7863
1520-5126
DOI:10.1021/ja072678l