Enantioselective Nozaki–Hiyama–Kishi allylation-lactonization for the syntheses of 3-substituted phthalides
作者:Sharad V. Kumbhar、Chinpiao Chen
DOI:10.1039/c8ra09575b
日期:——
A chromium-catalyzed enantioselective Nozaki–Hiyama–Kishi allylation of substituted (2-ethoxycarbonyl)benzaldehydes and subsequent lactonization to synthesize phthalides with an optimal enantioselectivity of 99%.
Synthetic Racemate and Enantiomers of Cytosporone E, a Metabolite of an Endophytic Fungus, Show Indistinguishably Weak Antimicrobial Activity
作者:Tomoya OHZEKI、Kenji MORI
DOI:10.1271/bbb.67.2584
日期:2003.1
The racemate and the enantiomers of cytosporone E [3-heptyl-4,5,6-trihydroxyphthalide (1)], a metabolite of the endophytic fungus, CR200 (Cytospora sp.), were synthesized. The key steps were (i) Sharpless asymmetric dihydroxylation of an alkene (8) and (ii) HPLC separation of the enantiomers of tert-butyldimethylsilyl ether (12) on a chiral stationary phase. The racemate and enantiomers of cytosporone E showed only weak antimicrobial activity with no difference among them.
合成了内生真菌CR200(Cytospora sp.)的代谢物细胞霉素E [3-庚基-4,5,6-三羟基邻苯二甲酸内酯(1)] 的外消旋体和其对映体。关键步骤为: (i) 烯烃(8)的Sharpless不对称二羟基化, (ii) 在手性固定相上进行的三丁基二甲基硅醚(12)对映体的高效液相色谱分离。细胞霉素E的外消旋体和对映体仅表现出微弱的抗菌活性,且之间没有差异。
Asymmetric Ruthenium‐Catalyzed C−H Activation by a Versatile Chiral‐Amide‐Directing Strategy
作者:Wenkun Chen、Jijun Jiang、Jun Wang
DOI:10.1002/anie.202316741
日期:2024.2.5
A versatile chiral amide directing group has been studied in the context of the ruthenium(II)-catalyzed asymmetric C−Hactivation. Six transformations have been achieved, affording a series of valuable chiral products. With this tool, concise syntheses of many natural products and biologically active compounds (e.g., Montroumarin, Cyclosporone E, Cyclosporone Q, Concentricolide, Chuangxinol, and Eleutherol)
在钌 (II) 催化的不对称 C−H 活化的背景下研究了一种多功能手性酰胺导向基团。已实现六次转化,提供了一系列有价值的手性产物。利用该工具,完成了许多天然产物和生物活性化合物(例如 Montroumarin、Cyclosporone E、Cyclosporone Q、Concentricolide、Chuangxinol 和 Eleutherol)的简明合成。