在氧气存在下照射非过渡金属氧化物粉末硅胶,氧化铝和氧化镁会导致单线态氧(1 O 2)的形成。使用两个特定的化学阱来检测1 O 2:1,2-二甲基环己烯和双键氘代的[ 2 H 6 ] -2,3-二甲基丁-2-烯。当照射在金属氧化物表面上时,两种化合物都给出了单线态氧反应的产物分布特征。这些结果支持先前的建议,即单线态氧是通过能量转移过程形成的,该过程涉及金属氧化物表面上的氧和激子。在相同反应条件下TiO 2显示没有产生1 O 2。
Homogeneous Decatungstate-Catalyzed Photooxygenation of Tetrasubstituted Alkenes: A Deuterium Kinetic Isotope Effect Study
作者:Ioannis N. Lykakis、Georgios C. Vougioukalakis、Michael Orfanopoulos
DOI:10.1021/jo061238u
日期:2006.11.1
The decatungstate W10O324- homogeneous photocatalyzed oxygenation of tetrasubstituted alkenes has been mechanistically studied. In all cases, allylic hydroperoxides are the major products. The primary inter- and intramolecular as well as the remote δ-secondary deuterium kinetic isotope effects for the photooxidation of the 2,3-dimethyl-2-butene and 1,1,1-trideuterio-7-methyl-2-(trideuteriomethyl)octa-2
已对四取代烯烃的去阳离子钨酸盐W 10 O 32 4-均相光催化氧化进行了机理研究。在所有情况下,烯丙基氢过氧化物都是主要产品。分子间和分子内以及远处的δ-次级氘动力学同位素效应对2,3-二甲基-2-丁烯和1,1,1-三叔甲基7-甲基-2-(三叔甲基)的光氧化作用octa-2,6-diene和产物分析表明在速率确定步骤中会析氢。为了比较,还研究了上述底物的单重态氧光敏氧化。
Solvent-Dependent Changes in the Triazolinedione-Alkene Ene Reaction Mechanism
作者:Georgios C. Vougioukalakis、Manolis M. Roubelakis、Mariza N. Alberti、Michael Orfanopoulos
DOI:10.1002/chem.200800920
日期:2008.10.29
The influence of the solvent on the triazolinedione-alkene enereactionmechanism has been investigated. Both inter- and intramolecularkineticisotopeeffects with tetramethylethylenes and 2,2,2-(trideuterio)methyl-7-methyl-2,6-octadiene-[D3]-1,1,1 provide, for the first time, strong evidence for changes in the mechanism of the reaction on going from non-protic to polar protic solvents. In non-protic
Intramolecular and Intermolecular Kinetic Isotope Effects (KIE) in the Nitrosoarene Ene Reaction: Experimental Evidence for Reversible Intermediate Formation
作者:Waldemar Adam、Oliver Krebs、Michael Orfanopoulos、Manolis Stratakis、Georgios C. Vougioukalakis
DOI:10.1021/jo0266240
日期:2003.3.1
The intramolecular and intermolecular kinetic isotopeeffects (KIE) have been determined for the nitrosoarene ene reaction with deuterium-stereolabeled 2,3-dimethyl-2-butenes (TME). trans-TME-d(6) (k(H)/k(D) = 3.0) and gem-TME-d(6) (k(H)/k(D) = 4.0) show large intramolecular primary isotopeeffects. In contrast, the intramolecular competition in cis-TME-d(6) (k(H)/k(D) = 1.5) and the intermolecular
Homoallyl cyanide and N-allylketene imine; a [3,3]sigmatropic equilibrium
作者:Reinhard Brückner、Rolf Huisgen
DOI:10.1016/s0040-4039(00)76885-7
日期:1994.5
δ-unsaturated nitrile 2 equilibrates at room temperature with the N-allylketene imine 3. Deuterium labeling established an intramolecular rearrangement, and the small influence of solvent polarity on the rate constants is in accordance with a concerted [3,3]sigmatropic shift.