Singlet Oxygen Photo-Oxygenation in Water/Pluronic F-127 Hydrogels: Increased Reaction Efficiency Coupled with a Switch in Regioselectivity
作者:Axel G. Griesbeck、Johannes Uhlig、Thomas Sottmann、Lhoussaine Belkoura、Reinhard Strey
DOI:10.1002/chem.201202296
日期:2012.12.7
efficient microenvironments for photochemical reactions, as demonstrated for singletoxygen reactions of monoalkenes. Nonpolar substrates are localized in the nanosized polymer compartment, which can be visualized by neutron scattering. The efficiency of 1O2 reactions is strongly increased for tiglate derivatives and the regioselectivity of the ene reaction of trisubstituted alkenes is completely switched
Pluronic F-127水凝胶是光化学反应的高效微环境,正如单烯烃的单线态氧反应所证明的那样。非极性基质位于纳米级聚合物隔室中,可以通过中子散射将其可视化。tiglate衍生物的1 O 2反应效率大大提高,与溶液相相比,三取代烯烃的烯反应的区域选择性完全切换,与沸石内光氧合相比,其区域选择性完全反转。
An entirely solvent-free photooxygenation of olefins under continuous flow conditions
作者:Patrick Bayer、Axel Jacobi von Wangelin
DOI:10.1039/d0gc00436g
日期:——
The choice of solvents is key to the success of this oxyfunctionalization with direct impact on the solubility of substrates, the lifetime of the reactive oxygen species, and the up-scaling of the process. We report an entirely solvent-free continuous-flow photooxygenation that operates at very high substrate/sensitizer ratios and enables high space–time yields.
Preparative Oxidation of Organic Compounds in Microemulsions with Singlet Oxygen Generated Chemically by the Sodium Molybdate/Hydrogen Peroxide System<sup>1</sup>
作者:Jean-Marie Aubry、Sabine Bouttemy
DOI:10.1021/ja9644079
日期:1997.6.1
designed to oxidize hydrophobic organic substrates with singletoxygen (1O2, 1Δg) generated from the disproportionation of hydrogenperoxidecatalyzed by molybdateions. The microemulsion was prepared by mixing methylene chloride, sodium dodecylsulfate, n-butanol, and aqueous molybdate. Flash photolysis studies have shown that in such media singletoxygen exhibits a similar kinetic behavior that under homogeneous
specific trapping have shown that CaO(2).2H(2)O(2) can be stored for several days at -80 degrees C and that the yield of (1)O(2) is equal to 25%. Oxidation of typical organic substrates in methanol or THF through [4 + 2] or [2 + 2] cycloaddition and ene reaction have been carried out on a preparative scale with total conversion and selectivity.
Glycol-modified molybdate catalysts for efficient singlet oxygen generation from hydrogen peroxide
作者:Joos Wahlen、Dirk De Vos、Walther Jary、Paul Alsters、Pierre Jacobs
DOI:10.1039/b704238h
日期:——
Pretreatment of molybdate-exchanged layered double hydroxides in polyalcohols such as ethylene glycol affords heterogeneous catalysts showing largely improved oxidant efficiency compared to the unmodified materials.