Bis(trimethylsilyl) peroxide, BTSP
Bis(trimethylsilyl) peroxide is an oxygen source that enables a controlled release of H2O2 under mostly anhydrous conditions. Catalytic amounts of a proton source (H2O, MeOH) are needed to promote hydrolysis. The hexamethyldisiloxane, which is formed as byproduct, has a boiling point of 100°C and can be evaporated toghether with the organic solvent, which simplifies the work-up. Although BTSP has a low active oxygen content, it can form hazardous 100% H2O2 in water and acid and can cause explosions in contact with metal needles. The use of plastic or glass pipets is recommended (J. Org. Chem., 2001, 66, 4713, footnote 12).
Organometallic rhenium species (e.g., CH3ReO3) can be replaced by less expensive inorganic rhenium oxides (e.g., Re2O7, ReO3(OH), and ReO3) using bis(trimethylsilyl) peroxide (BTSP) as oxidant in place of aqueous H2O2. Using a catalytic amount of a proton source, controlled release of hydrogen peroxide helps preserve sensitive peroxorhenium species and enables catalytic turnover to take place.
A. K. Yudin, J. P. Chiang, H. Adolfsson, C. Copéret, J. Org. Chem., 2001, 66, 4713-4718.
Using bis(trimethylsilyl) peroxide as the oxidant and simply exchanging dichloromethane, the classical solvent for Baeyer-Villiger oxidation, for the ionic liquid bmimNTf2, results in increased product yields. 1-Butyl-3-methylimidazolium trifluoromethanesulfonate can replace both the solvent and BF3ˇOEt2 as catalyst. This method gives lactones in high yields with the possibility of ionic liquid recycling.
S. Baj, A. Chrobok, R. Słupska, Green Chem., 2009, 11, 279-282.