High-yielding syntheses of 4(5)-substituted imidazoles via organolithium intermediates. the utility of sulphonamide n-protection and silicon-containing blocking groups
作者:Andrew J. Carpenter、Derek J. Chadwick
DOI:10.1016/s0040-4020(01)90617-9
日期:1986.1
-Protection of imidazole as its ,-dimethyl-sulphonamido derivative, and blocking of the 2-position with the triethylsilyl group permits regioselective 5-metallation with sec-butyl-lithium. The resulting organolithium intermediates react with a range of electrophiles and the products are easily deprotected to give the 4(5)-substituted NH-free imidazoles in good to excellent yields. Isolation of the