Organic Synthesis Laboratory, School of Basic Sciences , Indian Institute of Technology Bhubaneswar , Argul, Khurdha 752050 , Odisha , India.
J Org Chem. 2019 Sep 20;84(18):11596-11603. doi: 10.1021/acs.joc.9b01521. Epub 2019 Sep 4.
Short and scalable total syntheses of lamellarin G trimethyl ether, lamellarin D trimethyl ether, lamellarin H, lamellarin η, dihydrolamellarin η, and lamellarin U have been realized in four to six linear steps with an overall yield of ≤22%. Highlights of the synthesis include single-step access to the central 1,2,4-trisubstituted pyrrole core in a highly regioselective manner via a one-pot [3+2] cycloaddition/elimination/aromatization sequence-based domino process. Subsequent, palladium-mediated double C-H oxidative coupling in a single-pot operation provides access to the pentacyclic coumarin-fused pyrrolo-dihydroisoquinoline core present in lamellarins.
已实现了 lamellarin G 三甲醚、lamellarin D 三甲醚、lamellarin H、lamellarin η、dihydrolamellarin η 和 lamellarin U 的简短、可扩展的全合成，总收率≤22%，具有 4 至 6 步线性步骤。合成的重点包括通过一锅[3+2]环加成/消除/芳构化序列基多米诺过程以高区域选择性一步法获得中央 1,2,4-三取代吡咯核心。随后，在一锅操作中钯介导的双 C-H 氧化偶联提供了进入 lamellarins 中存在的五环香豆素稠合吡咯二氢异喹啉核心的途径。
