AZIDO (TEMPO variants)
TEMPO derivatives (i.e., AZADO) and alternatives
A large number of TEMPO variants exist based on the 2, 2, 6, 6,-tetramethylpiperidine motif. In recent years, a number of structurally diverse nitroxide radical oxidation catalysts have appeared. A drawback is lack of commercial availability, although more are becoming commercial or readily prepared. A key feature is that these catalysts often show positive rate enhancements compared to TEMPO – often several orders of magnitude. The mechanism of action is identical, requiring a terminal oxidant like NaOCl to drive the catalytic cycle.
