Highly Chemo- and Stereoselective Palladium-Catalyzed Transfer Semihydrogenation of Internal Alkynes Affording <i>cis</i>-Alkenes
作者:Jie Li、Ruimao Hua、Tao Liu
DOI:10.1021/jo100247a
日期:2010.5.7
DMF (N,N-dimethylformamide)/KOH was found to be an efficient hydrogen source in the Pd(OAc)2-catalyzed transfer semihydrogenation of various functionalized internal alkynes to afford cis-alkenes in good to high yields with excellent chemo- and stereoselectivity. This catalytic process was also applied to the synthesis of analogues of combretastatin A-4.
The photophysical and photochemical behaviour of a series of diarylethenes has been investigated experimentally. For the same compounds the potential-energy curves of trans→cis photoisomerisations and the ethenic bond orders in the S1 and T1 states have been calculated. The purpose of the study is to assess which properties of the aryls govern the photophysical behaviour of the diarylethenes. It is found that the relative energies of the La and Lb states of the larger aryl with respect to the ethene Bu state determine to a large extent the photophysical and photochemical properties of the diarylethenes.
实验研究了一系列二元乙烷的光物理和光化学行为。对于相同的化合物,还计算了反式→顺式光异构化的势能曲线以及 S1 和 T1 状态下的乙烯键顺序。这项研究的目的是评估芳基的哪些特性会影响二元乙烷的光物理行为。研究发现,较大芳基的 La 和 Lb 态相对于乙烯 Bu 态的相对能量在很大程度上决定了二元乙烷的光物理和光化学性质。
Wittigreaction was performed in Deep Eutectic Solvents with high yields, wide scope, facile TPPO (triphenyl phosphine oxide) removal and scalability of the process.
focussed library of trans-stilbene compounds through Wittig and other base catalysed condensationreactions is presented. The synthesized stilbenes were screened for their inhibitory potential against murine tyrosinase activity to explore the structure activity relationship (SAR). Presence of electron withdrawing group (-CN) at the double bond and hydroxyl group or halogen atom especially at para-position