Polar effects in hydrogen abstraction from benzaldehydes—I
作者:K.H. Lee
DOI:10.1016/s0040-4020(01)98675-2
日期:1968.1
The relative rates of hydrogenabstraction by the trichloromethylradical have been determined for nine m- and p-substituted benzaldehydes by means of competitive reactions using ethylbenzene as referecne standard. A polar effect ϱ = 0·74) was shown to be correlated by the Hammett equation with the σ constant, and the anomalous behaviour of the p-MeO and p-PhO substituents is discussed. The deuterium
由三氯甲基自由基夺氢的相对速率已经确定九个米-和p通过使用乙苯作为referecne标准的竞争性反应的手段-取代的苯甲醛。通过Hammett方程显示出极性效应ϱ = 0·74)与σ常数相关,并讨论了p -MeO和p -PhO取代基的异常行为。发现氘同位素效应K H / K D在80°下为2·4。
Enantioselective Synthesis of Cyclic Sulfamidates via Pd-Catalyzed Hydrogenation
Using Pd(CF3CO2)(2)/(SS)-f-binaphane as the catalyst, an efficient enantioselective synthesis of cyclic sulfamidates was developed via asymmetric hydrogenation of the corresponding cyclic imines in 2,2,2-trifluoroethanol at room temperature with high enantioselectivities (up to 99% ee).
Kevill Dennis N., Knauss Donald C., J. Chem. Soc. Perkin Trans. 2, (1993) N 3, S 307-312