Controlled and Predictably
Selective Oxidation of
Activated and Unactivated C(sp3)–H Bonds Catalyzed
by a Molybdenum-Based Metallomicellar Catalyst in Water
posted on 2022-01-31, 13:04authored byPrabaharan Thiruvengetam, Dillip Kumar Chand
The synthesis of carbonyl derivatives
from renewable feedstocks,
by direct oxidation/functionalization of activated and unactivated
C(sp3)–H bonds under a controlled and predictably
selective fashion, especially in late stages, remains a formidable
challenge. Herein, for the first time, cost-effective and widely applicable
protocols for controlled and predictably selective oxidation of petroleum
waste and feedstock ingredients like methyl-/alkylarenes to corresponding
value-added carbonyls have been developed, using a surfactant-based
oxodiperoxo molybdenum catalyst in water. The methodologies use hydrogen
peroxide (H2O2) as an environmentally benign
green oxidant, and the reactions preclude the need of any external
base, additive, or cocatalyst and can be operated under mild eco-friendly
conditions. The developed protocols show a wide substrate scope and
eminent functional group tolerance, especially oxidation-liable and
reactive boronic acid groups. Upscaled multigram synthesis of complex
steroid molecules by late-stage oxidation proves the robustness and
practical utility of the current protocol since it employs an inexpensive
recyclable catalyst and an easily available oxidant. A plausible mechanism
has been proposed with the help of few controlled experiments and
kinetic and computational studies.