Tag Archives: TEMPO

(2,2,6,6-Tetramethylpiperidin-1-yl)oxyl, or (2,2,6,6-tetramethylpiperidin-1-yl)oxidanyl or TEMPO is the chemical compound with the formula (CH2)3(CMe2)2NO. This heterocycle is a red-orange, sublimable solid. As a stable radical, it has applications throughout chemistry and biochemistry. TEMPO was discovered by Lebedev and Kazarnowskii in 1960. It is prepared by oxidation of 2,2,6,6-tetramethylpiperidine. TEMPO is widely used as a radical trap, as a structural probe for biological systems in conjunction with electron spin resonance spectroscopy, as a reagent in organic synthesis, and as a mediator in controlled free radical polymerization. The stability of this radical is attributed to the steric protection provided by the four methyl groups adjacent to the nitroxyl group.
TEMPO is employed in organic synthesis as a catalyst for the oxidation of primary alcohols to aldehydes. The actual oxidant is the N-oxoammonium salt. In a catalytic cycle with sodium hypochlorite as the…