Reaction of Tungsten η<sup>3</sup>-<i>anti</i>-Pentadienyl Compounds with Reactive Olefins and Isocyanates: [5 + 2] Cycloaddition versus Acylation
作者:Tesa-Chyi Yueh、Shie-Fu Lush、Gene-Hsian Lee、Shie-Ming Peng、Rai-Shung Liu
DOI:10.1021/om960704a
日期:1996.12.24
(−40 °C) gave a 75% yield of CpW(CO)3(η3-anti-2-CO2Me-4-methylpentadienyl) (2). Compound 2 reacted with TCNE to afford the novel [5 + 2] cycloaddition adduct 3 in 62% yield; the molecular structure of 3 showed a 1,2-shift of the tungsten fragment, indicating a η4-s-cis-diene reaction intermediate. The reaction of 2 with reactive isocyanates RNCO (R = PhSO2, CH3C6H4SO2) in cold CH2Cl2 produced 4a (R =
在冷乙醚(−40°C)中用CF 3 SO 3 H和MeOH依次处理CpW(CO)3(CH 2 C CCMe CH 2)(1),得到75%的CpW(CO)3(η)3 -反-2-CO 2 ME-4-methylpentadienyl)(2)。化合物2与TCNE反应,以62%的收率得到新颖的[5 + 2]环加成加合物3。的分子结构3显示了钨片段的1,2-移位,指示η 4 - s ^ -顺-二烯反应中间体。的反应2具有反应性的异氰酸酯RN Ç O(R = PhSO 2,CH 3 Ç 6 ħ 4 SO 2)在冷CH 2氯2产生图4a(R = PhSO 2)和图4b(R = CH 3 Ç 6 ħ 4 SO 2)的产率分别为82%和87%;根据4a的X射线衍射研究,这两种化合物可被视为2的酰化衍生物。