Zr-Catalyzed Kinetic Resolution of Allylic Ethers and Mo-Catalyzed Chromene Formation in Synthesis. Enantioselective Total Synthesis of the Antihypertensive Agent (<i>S</i>,<i>R</i>,<i>R</i>,<i>R</i>)-Nebivolol
作者:Charles W. Johannes、Michael S. Visser、Gabriel S. Weatherhead、Amir H. Hoveyda
DOI:10.1021/ja981378o
日期:1998.8.1
resolutions of cycloheptenyl styrenyl ethers 8 and 16, which are subsequently treated with 4 mol % Mo(CHCMe2Ph)(N(2,6-(i-Pr)2C6H3))(OCMe(CF3)2)2 to afford chiral nonracemic 2-substituted chromenes (R,R)-9 and (S,R)-17. Since the present retrosynthetic analysis dissects the molecule into two chromene fragments, both the (R) and (S) antipodes of (EBTHI)Zr catalyst are required. Accordingly, Buchwald's
描述了抗高血压剂 (S,R,R,R)-奈必洛尔 (3) 的第一个对映选择性全合成。该合成包括环庚烯基苯乙烯基醚 8 和 16 的高效 (EBTHI) Zr 催化动力学拆分,随后用 4 mol % Mo(CHCMe2Ph)(N(2,6-(i-Pr)2C6H3))(OCMe (CF3)2)2 得到手性非外消旋 2-取代色烯 (R,R)-9 和 (S,R)-17。由于目前的逆合成分析将分子分解为两个色烯片段,因此需要 (EBTHI) Zr 催化剂的 (R) 和 (S) 对映体。因此,Buchwald 的高效拆分过程用于拆分外消旋-(EBI)ZrCl2(来自市售外消旋-(EBI)ZrCl2 的催化氢化),从而通过单一过程获得两种必需的过渡金属手性催化剂。