Studies towards the Taming of the ‘Carbocation’ in the Regioselective Ring Opening of Epoxides to Allylic Alcohols
作者:William Motherwell、Helen Chapman、Karim Herbal
DOI:10.1055/s-0029-1219373
日期:2010.3
Regioselective isomerisation of epoxides to allylic alcohols can be achieved using p-toluenesulfonic acid in the presence of 1,3-dimethylimidazolidin-2-one.
Gas phase generation of singlet oxygen at atmospheric pressure
作者:Walter C. Eisenberg、Alan Snelson、Ronald Butler、James Veltman、Robert U. Murray
DOI:10.1016/0040-4039(81)80104-9
日期:1981.1
Evidence is presented for the gas phase generation of singletoxygen using heterogeneous photosensitization and atmosphericpressure.
提出了利用非均相光敏化和大气压力产生单线态氧的气相的证据。
Photochemical generation of singlet oxygen on non-transition-metal oxide surfaces
作者:Kirk Gohre、Glenn C. Miller
DOI:10.1039/f19858100793
日期:——
Irradiation of the non-transition-metaloxide powders silica gel, aluminium oxide and magnesium oxide in the presence of oxygen results in the formation of singletoxygen (1O2). Two specific chemical traps were used to detect 1O2: 1,2-dimethylcyclohexene and geminally deuterated [2H6]-2,3-dimethylbut-2-ene. Both compounds gave product distributions characteristic of singlet-oxygen reactions when irradiated
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。
Dicyanoanthracene sensitized photo-oxygenation of olefins
作者:Christopher S. Foote
DOI:10.1016/s0040-4020(01)96596-2
日期:1985.1
at least two mechanisms : (1) enhanced intersystem crossing, in which 1DCA is quenched by interaction with the olefin, leading to a low yield of 3DCA, which subsequently reacts with oxygen to produce singlet oxygen; and (2) direct reaction of 1DCA with oxygen. At limiting high oxygen concentration, this process produces 2 mol of singlet oxygen for each mol of 1DCA quenched; the mechanism involves energy
Mechanistic study on the photo-oxidation of α-diketones
作者:Yasuhiko Sawaki
DOI:10.1016/s0040-4020(01)96593-7
日期:1985.1
The mechanism for photo-oxidation of α-diketones in the presence of olefins has been studied, focusing on the interaction of triplet diketones with O2. Two types of reactions occur competitively. One is the formation of 1O2 by energy transfer to O2 and the other is the addition of O2 to triplet diketone, which yields acylperoxy radicals leading to the radical epoxidation of olefins. Ratios of the two
研究了在烯烃存在下α-二酮的光氧化机理,重点研究了三重二酮与O 2的相互作用。两种类型的反应竞争发生。其一是形成1 Ò 2通过能量转移至O 2,而另一个是加法的O- 2至三重二酮,这产生acylperoxy自由基导致烯烃的环氧化基团。由1 O 2产物和环氧化物的产率确定两个反应的比率。对于大多数二酮,形成1 O 2的量子产率相当高,在0.3-0.8范围内。但是环氧化物的收率是0.001-0.5的较宽范围。虽然1 O 2形成和O 2加成三重二酮的比率范围从联乙酰的29:71到MESItil的1:99,但通过改变溶剂或温度,该比率保持恒定。后者的O 2加成反应按MeCOCOMe> PhCOCOMe> PhCOCOPh的顺序降低,但是m-和p-取代基对苯甲的影响不显着,表明O 2作为中性双自由基的添加。在特殊情况下,添加O 2对于空间上不可及的metilil和某些环状α-二酮无效。1 O 2的机理