85702-23-4Relevant academic research and scientific papers
Kinetics of reduction of a series of imidazolium ions and cobalt(III)-imidazole complexes by 1-hydroxy-1-methylethyl radicals
Bakac, Andreja,Butkovi?, Vjera,Espenson, James H.,Lovri?, Jasna,Orhanovi?, Matko
, p. 4323 - 4326 (2008/10/08)
The rates of electron transfer from ?C(CH3)2OH to a series of imidazolium ions and to a series of (NH3)5Co(X-Im)3+ complexes have been measured. A kinetic competition method based on the homolytic scission of the chromium-carbon bond in (H2O)5CrC(CH3)2OH2+ was used to evaluate rate constants for the reducing agent ?C(CH3)2OH. In both series the rate constants show sensitivity to substituents on the imidazole ring. The rate constants for the free imidazolium ions are correlated by an LFER to the relative electron affinity of the imidazolium ion. The rate constants for the cobalt(III)-imidazole complexes are correlated by the lowest energy d-d absorption band of the complexes.
IMIDAZOLE-PROMOTED HYDROLYSIS OF OXAPHOSPHOLENE ESTERS. NUCLEOPHILIC VS. GENERAL BASE CATALYSIS.
Macomber
, p. 4386 - 4389 (2007/10/02)
A 2. 4-fold excess of imidazole (Im) accelerated the hydrolysis of 5,5-dimethyl-2-methoxy-1,2-oxaphosphol-3-ene 2-oxide (2a) in 50% aqueous methanol by a rate factor greater than 50. The reaction was first order in Im and led to the imidazolium salt (3-Im) of 5,5-dimethyl-2-hydroxy-1,2-oxaphosphol-3-ene 2-oxide and methanol via two independent routes. One route involved direct nucleophilic attack at the methoxy carbon; the other route was a multistep process with nucleophilic attack at phosphorus to give a ring-opened intermediate which was observed by **1H NMR. Possible intermediate 5,5-dimethyl-2-imidazoyl-1,2-oxaphosphol-3-ene 2-oxide was prepared and demonstrated to be highly reactive toward solvolysis in methanol and aqueous methanol. The Im-promoted hydrolysis was interpreted as involving general base catalysis.
