Carbometalation–Carboxylation of 2,3-Allenols with Carbon Dioxide: A Dramatic Effect of Halide Anion
作者:Suhua Li、Bukeyan Miao、Weiming Yuan、Shengming Ma
DOI:10.1021/ol4000197
日期:2013.3.1
and stereoselective carbomagnesiation of 2,3-allenols with Grignard reagents may smoothly react with carbon dioxide to afford 2(5H)-furanones. A dramatic effect of the halide anion from the Grignard reagent (Br vs Cl) for CO2 activation was observed. The reaction proceeded smoothly under mild conditions to afford the products in 58–93% yields.
用格氏试剂通过CuCl介导的2,3-烯醇的高度区域选择性和立体选择性碳还原反应形成的环状有机金属中间体可与二氧化碳平稳反应,得到2(5 H)呋喃酮。观察到了来自格氏试剂的卤化物阴离子(Br vs Cl)对CO 2活化的显著作用。反应在温和的条件下平稳进行,以58-93%的收率得到产物。
Preparation and reactions of samarium diiodide in nitriles
作者:Béatrice Hamann、Jean-Louis Namy、Henri B. Kagan
DOI:10.1016/0040-4020(96)00861-7
日期:1996.11
Samarium diiodide can be prepared from samarium metal in various nitriles. Because of its chemical inertness pivalonitrile is the most suitable solvent. Organic reactions mediated by SmI2 are slower than in THF, but selectivities are often improved. Reactions are greatly accelerated by addition of catalytic amounts of some transition metal salts.
The first facile, efficient, atom-economical and regioselective palladium-catalyzed direct C–P cross-coupling of unprotected allenic alcohols with H-phosphonates for the one-pot synthesis of structurally diverse multisubstituted 2-phosphinoyl-1,3-butadienes was developed. This strategy would enrich the allene chemistry and afford new scaffolds to construct complex molecular skeletons.
Divalent lanthanide derivatives in organic synthesis. 1. Mild preparation of samarium iodide and ytterbium iodide and their use as reducing or coupling agents
作者:P. Girard、J. L. Namy、H. B. Kagan
DOI:10.1021/ja00528a029
日期:1980.4
Organosamariums: preparation using diiodosamarium and reactivity in tetrahydropyran
作者:Béatrice Hamann-Gaudinet、Jean-Louis Namy、Henri B. Kagan
DOI:10.1016/s0022-328x(98)00666-4
日期:1998.9
Diiodosamarium prepared in tetrahydropyran reduces allylic, benzylic and alkyl halides at 0 or -15 degrees C to give organosamariums which are stable under these conditions. The reactivity of these organometallics has been explored, showing that they are very selective reagents. (C) 1998 Elsevier Science S.A. All rights reserved.