Oxyfunctionalization of unactivated C–H bonds in triterpenoids with tert-butylhydroperoxide catalyzed by meso-5,10,15,20-tetramesitylporphyrinate osmium(II) carbonyl complex

Porphyrins as Catalysts in Scalable Organic Reactions

“…The oxy-functionalization system with osmium-porphyrins as catalyst regioselectively hydroxylates one of the inactivated tertiary C-H bonds in dihydrofaradiol diacetate to form the corresponding alcohol in 50% yield (Scheme 17). The functionalization of triterpenoids with the oxidant system afforded a variety of novel oxygenated derivatives in one-step with good isolated yields [69]. Other types of porphyrins have been explored for this hydroxylation reaction, and in 2007, Idemori and co-workers studied Mn(III)-tetrapyridylporphyrin as catalyst in the hydroxylation of cyclohexene [67].…”

“…Other types of porphyrins have been explored for this hydroxylation reaction, and in 2007, Idemori and co-workers studied Mn(III)-tetrapyridylporphyrin as catalyst in the hydroxylation of cyclohexene [67]. Iida and co-workers have shown that the combination of tert-butyl hydroperoxide (TBHP) and the osmium(II) carbonyl complex of meso-tetramesitylporphyrin [Os(TMP)(CO)] as oxygen donor and catalyst respectively (Scheme 16), is an efficient and versatile oxidation system for the functionalization of bioactive molecules, like bile acids [68] and terpenoids [69]. The oxy-functionalization system with osmium-porphyrins as catalyst regioselectively hydroxylates one of the inactivated tertiary C-H bonds in dihydrofaradiol diacetate to form the corresponding alcohol in 50% yield (Scheme 17).…”

“…The functionalization of triterpenoids with the oxidant system afforded a variety of novel oxygenated derivatives in one-step with good isolated yields [69]. …”

“…The oxy-functionalization system with osmium-porphyrins as catalyst regioselectively hydroxylates one of the inactivated tertiary C-H bonds in dihydrofaradiol diacetate to form the corresponding alcohol in 50% yield (Scheme 17). The functionalization of triterpenoids with the oxidant system afforded a variety of novel oxygenated derivatives in one-step with good isolated yields [69].…”

“…Iida and co-workers have shown that the combination of tert-butyl hydroperoxide (TBHP) and the osmium(II) carbonyl complex of meso-tetramesitylporphyrin [Os(TMP)(CO)] as oxygen donor and catalyst respectively (Scheme 16), is an efficient and versatile oxidation system for the functionalization of bioactive molecules, like bile acids [68] and terpenoids [69]. Other types of porphyrins have been explored for this hydroxylation reaction, and in 2007, Idemori and co-workers studied Mn(III)-tetrapyridylporphyrin as catalyst in the hydroxylation of cyclohexene [67].…”