据报道,以环己-1,4-二烯为正式氢源的1,1-二取代烯烃的无过渡金属转移加氢反应。该过程由B(C 6 F 5)3介导的氢化物从二氢替代物中的提取开始,形成布朗斯台德酸性Wheland络合物和[HB(C 6 F 5)3 ] -。一系列的质子和氢化物转移到烯烃底物上,然后生成烷烃。尽管涉及多种碳正离子中间体,但通过在C1和C5以及在C1和C5处使用带有甲基的环己-1,4-二烯可以大大抑制竞争性反应通道,例如二氢释放和反应物的阳离子二聚。 C3位置,氢化物提取的位置。烯烃浓度是另一个关键因素。通过计算分析了各种反应途径,得出了与实验观察结果完全吻合的机理图。
Application of a Ruthenium-Catalyzed Allylation–Cycloisomerization Cascade to the Synthesis of (±)-Herbindole A
作者:Edgar Haak、Nora Thies、Martin Stürminger
DOI:10.1055/s-0036-1588124
日期:——
A short and efficient total synthesis of the cytotoxic cyclopent[g]indole alkaloid (±)-herbindole A from dihydromesitylene has been achieved by incorporating a ruthenium-catalyzed allylation–cycloisomerization cascade reaction as the key step. The protocol has also been applied to the synthesis of the unnatural trans-epimer of the marine natural product.
Perfluoroalkylated Main‐Group Element Lewis Acids as Catalysts in Transfer Hydrogenation
作者:Julia Bader、Alexander F. G. Maier、Jan Paradies、Berthold Hoge
DOI:10.1002/ejic.201700524
日期:2017.6.30
Transfer hydrogenation plays an important part in organic chemistry. Recently, strong Lewis acids like B(C6F5)3 have been introduced as a catalyst for these reactions. We successfully employed the Lewis acid (C2F5)3PF2 as a catalyst in the transfer hydrogenation between 1,3,5-trimethylcyclohexa-1,4-diene and 1,1-diphenylethylene. Surprisingly, the treatment of the diene alone with a catalytic amount
Asymmetric transfer hydrogenation of ketones using amino alcohol and monotosylated diamine derivatives of indane
作者:Matthew J. Palmer、Jennifer A. Kenny、Tim Walsgrove、Aparecida M. Kawamoto、Martin Wills
DOI:10.1039/b108538g
日期:2002.1.23
A series of 1,2-amino alcohol and 1,2-monotosylated diamine derivatives of indane have been applied as ligands in the asymmetric ruthenium(II)-catalysed transfer hydrogenation reaction of a series of ketones. Of these, the cis-1-aminoindan-2-ol derivative gives some of the highest asymmetric inductions reported for any amino alcohol ligand in this application.
A straightforwardroute to polyols, amino polyols, polysubstituted lactols and lactones from readily available arenes has been devised. It uses a three- or four-step sequence involving a Birch reduction of the arene, followed by desymmetrization through dihydroxylation or aminohydroxylation and, lastly, ozonolysis of the remaining olefin. Depending on the ozonolysis workup conditions, cyclic or acylic