描述了 dictyodendrin B 和 E 的简明全合成以及 dictyodendrin C 的正式合成。钯催化的 Larock 吲哚合成用于形成高度取代的吲哚核心,钯介导的一锅连续 Buchwald-Hartwig 胺化/C-H 活化反应用于构建关键的吡咯[2,3-c]咔唑核。还讨论了不成功的合成策略。
Synthesis and anticancer studies of Michael adducts and Heck arylation products of sesquiterpene lactones, zaluzanin D and zaluzanin C from <i>Vernonia arborea</i>
作者:Tushar R. Valkute、Eswar K. Aratikatla、Neha A. Gupta、S. Ganga、Manas K. Santra、Asish K. Bhattacharya
DOI:10.1039/c8ra06238b
日期:——
2 were isolated from the leaves of Vernonia arborea. Several diverse Michaeladducts (3–22) and Heck arylation analogs (23–34) of 1 have been synthesized by reacting with various amines and aryl iodides, respectively and were assayed for their in vitro anticancer activities against human breast cancer cell lines MCF7 and MDA-MB-231. Among all the synthesized analogs, Michaeladducts 9 and 10 showed
从斑鸠菊的叶子中分离出含有α-亚甲基-γ-内酯、zaluzanin D 1和zaluzanin C 2的倍半萜内酯。通过分别与各种胺和芳基碘化物反应合成了几种不同的迈克尔加合物 ( 3-22 ) 和1的Heck 芳基化类似物 ( 23-34 ),并测定了它们对人乳腺癌细胞系 MCF7和MDA-MB-231。在所有合成的类似物中,迈克尔加合物9和10与1相比显示出更好的抗癌活性。然而,在这些化合物中,只有10对正常乳腺上皮 MCF10A 细胞的细胞毒性作用最小。我们详细的机理研究表明,化合物9和10通过诱导细胞凋亡发挥其抗增殖活性,从而抑制癌细胞增殖,化合物10可能是设计潜在抗癌化合物的先导化合物。
Total synthesis of indole-3-acetonitrile-4-methoxy-2-C-β-d-glucopyranoside. Proposal for structural revision of the natural product
作者:Akop Yepremyan、Thomas G. Minehan
DOI:10.1039/c2ob25821h
日期:——
Indole-3-acetonitrile-4-methoxy-2-C-β-D-glucopyranoside (1), a novel C-glycoside from Isatis indigotica with important cytotoxic activity, has been prepared in ten steps from ethynyl-β-C-glycoside 3 and 2-iodo-3-nitrophenyl acetate 6. Key steps in the synthesis include a Sonogashira coupling and a CuI-mediated indole formation. NMR spectroscopic data for synthetic 1 differs from that reported for the natural product. A revised structure for the natural product, containing an alternate carbohydrate substituent, is proposed.
The aldol reactions of α-keto phosphonates and aldehydes were facilitated by an axially chiral biphenylprolinamide under mild conditions, affording the synthetically and pharmaceutically useful products in high yields and excellent enantioselectivities.
A Palladium-Catalyzed Ullmann Cross-Coupling/Reductive Cyclization Route to the Carbazole Natural Products 3-Methyl-9<i>H</i>-carbazole, Glycoborine, Glycozoline, Clauszoline K, Mukonine, and Karapinchamine A
作者:Qiao Yan、Emma Gin、Malgorzata Wasinska-Kalwa、Martin G. Banwell、Paul D. Carr
DOI:10.1021/acs.joc.7b00044
日期:2017.4.21
The title natural products 2–7 have been prepared by reductive cyclization of the relevant 2-arylcyclohex-2-en-1-one (e.g. 20) to the corresponding tetrahydrocarbazole and dehydrogenation (aromatization) of this to give the target carbazole (e.g. 4). Compounds such as 20 were prepared using a palladium-catalyzed Ullmann cross-coupling reaction between the appropriate 2-iodocyclohex-2-en-1-one and o-halonitrobenzene