Lima Heather M, Garcia-Barboza Beatriz J, Khatibi Nicole N, Lovely Carl J
Department of Chemistry & Biochemistry, University of Texas at Arlington, Arlington, TX 76019.
Tetrahedron Lett. 2011 Nov 2;52(44):5725-5727. doi: 10.1016/j.tetlet.2011.08.030.
The total syntheses of two alkaloids isolated from a marine sponge of the Leucetta sp. have been accomplished in 6 and 7 steps starting from a 4,5-diiodoimidazole derivative. Grignard mediated halogen-metal exchange was used to install the benzyl side chain. C2 substitution was accomplished via lithiation followed by quenching with trisyl azide which provided isonaamine C after hydrogenation. Isonaamidine E was then prepared from isonaamine C via introduction of the hydantoin ring by reaction with an activated parabanic acid.
从Leucetta属的一种海洋海绵中分离出的两种生物碱已从一种4,5-二碘咪唑衍生物开始，分别通过6步和7步完成了全合成。利用格氏试剂介导的卤素-金属交换反应引入苄基侧链。通过锂化反应进行C2位取代，然后用三叠氮基三苯甲烷淬灭，氢化后得到异诺胺C。然后，通过与活化的丙二酰脲反应引入乙内酰脲环，由异诺胺C制备异诺脒E。
